Supraparticles are hierarchically structured nanoparticle assemblies whose size and structural features, such as shape, surface roughness and porosity, critically influence performance in applications including energy storage and catalysis. While size and porosity can be reliably characterized, statistically meaningful ensemble-level methods for supraparticle shape assessment remain limited. In this work, we introduce a novel methodology for supraparticle shape estimation based on mercury intrusion porosimetry (MIP). We demonstrate that the characteristic two-stage intrusion profile corresponds to inter- and intra-supraparticle pores. Deconvolution of the pore size distributions enabled separation of these contributions, while assignment of their physical origin was realized by comparison of the extracted intrasupraparticle peaks with the pore size distributions of constituent nanoparticles. Using a systematic design of experiments to independently vary supraparticle size and shape, we establish that the degree of bimodality in pore size distributions strongly correlates with supraparticle shape. Quantitative shape descriptors obtained from scanning electron microscope-based circularity measurements were compared with statistical metrics of bimodality (Ashman's D and peak separation). A clear relationship emerged: supraparticles with higher circularity exhibited more pronounced bimodality. This work provides a statistically robust approach for simultaneous evaluation of supraparticle porosity and shape, enabling scalable quality control and process optimization in spray-drying. (c) 2026 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

In lithium‐ion battery silicon anodes, achieving reliable electrode processing, consistent electrochemical performance, and mechanically stable electrodes remains a challenge. One strategy to overcome these limitations is to assemble silicon–carbon (Si/C) nanoparticles with alloy‐like Si–C bonding into micrometer‐sized secondary particles (“supraparticles”) by spray drying. Without additives, the supraparticles are irregular and fragile; therefore, a polymeric binder is introduced to enable their controlled formation. This study establishes a foundational methodological framework to investigate the interactions of poly (acrylic acid) (PAA) with Si/C during supraparticle formation. In aqueous dispersion, PAA adsorbs onto the Si/C surface via weak hydrogen bonding. Subsequent ionization of carboxyl groups generates electrostatic repulsion between particles, stabilizing the dispersion. Upon spray drying, PAA forms a flexible, hydrogen‐bonded polymer network that crosslinks particles without covalent attachment to silanols. Drying electrodes at 120°C preserves this network, enabling volume‐change accommodation and high‐capacity retention (1996 mAh g−1 at the 100th cycle). In contrast, drying at 200°C generates PAA anhydrides and ester linkages with Si–OH groups, which reduce compliance, leading to lower Coulombic efficiency and faster fading (1353 mAh g−1 at the 100th cycle). These findings highlight binder chemistry as a key lever in designing durable Si/C electrodes.

Substrate-free graphene synthesized in the gas-phase is a promising material with high specific surface area, exceptional purity, and conductivity. Despite these desirable properties for various applications, the transformation from the powder to stable dispersions and functional thin films remains an obstacle for the technical integration of this material. In this work, this challenge is addressed through systematic dispersion, stabilization, and thin film formation studies. Space-and time-resolved analytical centrifugation was used as an in-situ method to quantify the sedimentation of graphene. Remarkable stability was achieved only when agglomeration of graphene particles was suppressed in either solvents such as N-(2-hydroxyethyl)-2-pyrrolidone, a non-toxic analog to N-methyl-2-pyrrolidone or using polymers and surfactants as stabilizers like carboxymethyl cellulose, polyvinylpyrrolidone, and N-didodecyldimethyl-ammonium bromide in aqueous dispersions. These optimized dispersions were used to fabricate thin films via Langmuir deposition, spray coating and ink-jet printing. Hall effect conductivity measurements in van der Pauw geometry, novel to this class of thin films, and surface analysis revealed conductive, yet rough and porous layers formed by spray coating (mobility up to approximate to 2 cm2/V center dot s, carrier density approximate to 50 center dot 1014 1/cm2) and compact micro-rough layers by Langmuir deposition (mobility approximate to 19 cm2/ V center dot s). This study provides insights into dispersion-process-structure-functionality relations and forms the framework for scalable dispersion formulation and thin film formation. The findings gained address major challenges for the device-integration of free-standing graphene for catalytic, adsorption and electronic applications.

The widespread reliance on evaluating electrocatalysts in electrochemical half-cells presents limitations that hinder a faster transition from academia to industry and can lead to premature exclusion of promising materials. To address these challenges, it is crucial to implement materials testing in application-relevant setups such as zero-gap full-cells. This transition can be achieved through implementing coherent workflows combining rapid evaluation of as-synthesized materials, electrode evaluation at different scales, and post-mortem analysis. This work presents a comparative study of three spray-flame synthesized lanthanum-based perovskite materials (LaMnO3, LaFeO3, and LaCoO3) for the oxygen evolution reaction under alkaline conditions, highlighting different behavior across scales. The research demonstrates how the interplay of materials properties, electrode engineering, and metal-support interactions influences performance under mild and harsh electrochemical conditions. Electrochemical half-cell testing consistently identifies LaFeO3 as the best oxygen evolution reaction catalyst across various configurations. This unforeseen behavior necessitates further investigation under application-relevant conditions. Full-cell testing at 500 mA cm-2 corroborates the trends observed in electrochemical half-cell testing, with LaFeO3 and LaMnO3 exhibiting comparable performance to LaCoO3 after prolonged operation. Furthermore, a degradation study under 1000 mA cm-2 highlights their potential for continued catalyst development. Advanced post-mortem techniques provide deeper insight into catalytic activity and structural changes, linking performance evolution to catalyst-substrate interactions and material-dependent surface changes under oxidative polarization. By bridging fundamental studies to application-relevant testing, this research provides knowledge and methods for accelerated material and electrode development.

The oxygen evolution reaction (OER) is an essential half-reaction in electrochemical energy conversion in aqueous media and a key to achieving improved water splitting efficiency. Perovskites, such as lanthanum cobalt oxide - LaCoO3, are promising materials due to their activity and stability in alkaline conditions. The present study focused on the influence of the support electrode on the intrinsic activity of the LaCoO3 perovskite catalyst towards OER. Nickel, iridium, platinum, and glassy carbon electrodes were used as support electrode for the assessment of the support effects. The trend of the overpotential at 10 mA cm-2 recorded by linear sweep voltammetry reveals a difference in the electrochemical behavior based on the support material used. In all cases, the coated electrode presented higher OER activity compared to the bare support electrodes, which indicates the active participation of the catalytic LaCoO3 in the reaction. In situ Fourier-transform infrared spectroscopy showed changes in *-OH adsorption and interfacial water structure, suggesting possible shifts in the OER mechanism. Additionally, in situ Raman provided insights regarding the influence of the support on the Co oxidation. Further insights were obtained from electrochemical impedance spectroscopy and Mott-Schottky analysis, where differences in the acceptor concentration on different support electrodes was observed. X-ray photoelectron spectroscopy, performed before and after electrochemical measurements, revealed changes in Co oxidation states and surface oxygen species, particularly significant on the Ni electrode, which may be due to the OER proceeding via the lattice oxygen mechanism. These findings highlight the crucial role of the support electrode during OER, emphasizing the importance of catalyst-support interactions in electrocatalyst design.

Achieving stable and dendrite-free zinc anodes remains a key barrier to the practical deployment of aqueous zincion batteries (ZIBs). Herein, we propose a synergistic interfacial engineering strategy that combines molecularlevel solvation regulation with in-situ polymer interface construction. A molecularly tailored ionic liquid monomer, 1-vinyl-3-aminopropyl imidazolium lysinate (VAIMLys), was designed by integrating an amino acid anion with a zincophilic imidazolium cation. Through in-situ polymerization, VAIMLys forms a conformal poly (ionic liquid) (PIL) interphase on the Zn surface. This dual-functional system simultaneously modulates the Zn2+ solvation structure and facilitates selective Zn2+ transport across the interface. Spectroscopic and computational analyses reveal that VAIMLys disrupts Zn2+-H2O and Zn2+-SO42- interactions, leading to a more stable solvation environment, which is favorable for suppressing water-induced side reactions. Meanwhile, the PIL interphase provides zincophilic coordination sites and electrostatic anion-trapping, establishing preferential Zn2+ conduction pathways and significantly enhancing the Zn2+ transference number (0.89). As a result, symmetric cells with the PIL-protected Zn anode deliver an ultra-long lifespan exceeding 4000 h at 1.0 mA cm- 2, while Zn||V2O5 full cells maintain 81.5 % capacity after 1500 cycles at 2 A g- 1. This work not only demonstrates a scalable and green approach to interface design but also offers mechanistic insights into the synergistic regulation of solvation chemistry and ion transport. The proposed strategy opens new avenues for designing advanced interphases in aqueous metal-ion batteries, contributing to the development of safe, long-lasting, and sustainable energy storage systems.

Developing effective non-noble metal electrocatalysts for the oxygen evolution reaction (OER) remains challenging due to limited active sites, poor electronic conductivity, and high overpotentials associated with the conventional adsorbate evolution mechanism (AEM). To address these limitations, a one-step spray drying method is employed to assemble high-surface-area La0.8Sr0.2CoO3 nanoparticles (LSCO-NP) into hierarchical supraparticles with ≈65% porosity and interconnected meso-/macropore networks. This architecture not only accelerates ion diffusion and interparticle electron transfer but also induces a mechanistic switch from the AEM to the lattice oxygen oxidation mechanism (LOM). La0.8Sr0.2CoO3 supraparticles (LSCO-SP) demonstrate significantly enhanced OER performance, requiring ∼300 mV lower overpotential at 100 mA cm-2 after 1 h compared to LSCO-NP. Moreover, LSCO-SP exhibit faster catalytic kinetics, evidenced by a smaller Tafel slope of 76.2 mV dec-1 versus 82.5 mV dec-1 and lower charge transfer resistance of 1.11 Ω versus 1.31 Ω for LSCO-NP. Structural analyses confirmed that the LSCO-SP maintained their integrity under OER conditions. Furthermore, post-mortem X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) analyses reveal an increased formation of oxygen vacancies (Ovac) in LSCO-SP, confirming that the supraparticle design tunes the lattice oxygen-mediated mechanism-oxygen vacancy site mechanism (LOM-OVSM), enhancing OER performance. The hierarchical structure of LSCO-SP highlights their potential as a novel building block for catalyst layers in renewable energy applications.

Developing effective non-noble metal electrocatalysts for the oxygen evolution reaction (OER) remains challenging due to limited active sites and poor electronic conductivity in mixed oxide catalysts. To address these limitations, a one-step spray drying method is employed to synthesize hierarchical La0.8Sr0.2CoO3 supraparticles (LSCO-SP) from high-surface-area nanoparticles (LSCO-NP). LSCO-SP demonstrate significantly enhanced OER performance, requiring ~300 mV lower overpotential at 100 mA cm⁻² after 1 hour compared to LSCO-NP. Moreover, LSCO-SP exhibit faster catalytic kinetics, evidenced by a smaller Tafel slope of 76.2 mV dec−1 versus 82.5 mV dec−1 and lower charge transfer resistance of 1.11 Ω versus 1.31 Ω for LSCO-NP. The enhanced activity of LSCO-SP is attributed to their hierarchical porous architecture, which promotes efficient ion diffusion, improved electron transport, and increased accessibility to electroactive sites. Structural analyses confirmed that the LSCO-SP maintained their integrity under OER conditions. Furthermore, postmortem X-ray photoelectron spectroscopy and electron paramagnetic resonance analyses reveal a higher concentration of oxygen vacancies in LSCO-SP, suggesting that the supraparticle design tunes the lattice oxygen mechanism, enhancing OER performance. The hierarchical structure of LSCO-SP highlights their potential as a novel building block for catalyst layers in renewable energy applications.

Pollutant degradation via titania photocatalysts holds significant potential. For 'smart' or knowledge-based design of photocatalysts, it is, however, important to understand the adsorption and degradation dynamics and their relationship with the particulate surface. Hansen solubility parameters (HSPs) can provide relevant information about the particle surface characteristics in dispersions. Herein, HSPs of six different titania materials including their composites with graphene are determined and they are related to the adsorption capacities of Bisphenol A and chloroform. The effect of the underlying synthesis procedures and graphene addition on the pollutant adsorption in the liquid phase is examined. The results show that the Hansen sphere radii correlate with the specific equilibrium adsorption capacities of the titania-based substrates for both pollutants. The type of crystallographic structure and the addition of graphene increase the adsorption dynamics and are accurately correlated with the HSP sphere radii. HSPs can thus serve as a characterization method for understanding liquid pollutant adsorption or, set in a wider context, the interaction of ligands or surface groups with a specific particle surface.

Bacterial infections, particularly those caused by drug-resistant strains, pose a significant global health threat. Photothermal therapy using iron-oxide nanoparticles shows promise in antibacterial treatments, but their use is limited by toxicity and nanoparticle agglomeration. This study presents a scalable spray-drying method to synthesize iron-oxide supraparticles, designed to enhance antibacterial efficacy while minimizing cytotoxicity. The iron-oxide supraparticles exhibited superior peroxidase-like activity compared to their nanoparticles, generating hydroxyl radicals through increased active sites. They demonstrated significant antibacterial activity against Escherichia coli and Staphylococcus aureus under near-infrared laser irradiation (1064 nm), achieving antibacterial rates of 77 % and 80 %, respectively, outperforming nanoparticles (25 % and 12 %). Their unique structure, with a larger diameter, rough surface, and internal porosity, contributed to improved antibacterial performance. Additionally, iron-oxide supraparticles maintained high cell viability in human dermal fibroblasts, confirming their biocompatibility. These supraparticles offer a promising approach for broad-spectrum antimicrobial applications without compromising host-cell viability.

This study investigates the influence of supraparticle sizes on the performance of Silicon/Carbon (Si/C) composite anodes for lithium-ion batteries. Supraparticles, hierarchically structured agglomerates produced via spray drying, enhance the processability of Si/C nanoparticles by improving handling, packing efficiency, and minimizing solid electrolyte interphase formation. We systematically explore how supraparticle size distributions and associated morphologies affect interparticle spacing, slurry rheology, coating density, and electrochemical performance. Medium-sized supraparticles (5.0–6.0 μm) with spherical shapes exhibit optimal properties, achieving the highest coating density (0.90 g cm⁻³) and providing precise control over layer thickness and porosity, resulting in uniform coatings. These supraparticles also deliver superior electrochemical performance, with a first-formation Coulombic efficiency of 87.5% and stable cycling, retaining 86.2% of capacity (relative to the third cycle) after 100 cycles. In comparison, smaller supraparticles (irregular shapes) exhibit increased interparticle spacing, resulting in less dense layers and higher SEI formation. These findings highlight the critical role of controlling supraparticle size and morphology to optimize electrode processing and performance, enabling scalable, high-performance energy storage solutions.

The oxygen evolution reaction (OER) is a key half-reaction in water splitting, where its sluggish kinetics are the limit for its overall efficiency [1]. Developing efficient, stable, and cost-effective OER catalysts remains a major challenge in electrochemical energy conversion. Perovskites have emerged as promising OER catalysts due to their tunable electronic structure, abundant active sites, and high structural stability under alkaline conditions. However, the electrochemical performance of perovskite catalysts is not solely governed by their intrinsic activity — the choice of support material plays a crucial role in charge transfer, catalyst dispersion, and overall interface stability [2]. In this study, lanthanum cobalt oxide (LCO) was deposited by drop casting method on glassy carbon (GC), nickel (Ni), platinum (Pt), and iridium (Ir) substrates to investigate how different supports affect its OER activity, providing insight into support–catalyst interactions that drive performance enhancement. The electrochemical measurements were conducted in a three-electrode configuration using 1 M KOH as the electrolyte, with a catalyst loading of 0.1 mg cm⁻² applied to the working electrode. A rotating disk electrode (RDE) setup was employed to ensure controlled mass transport and evaluate the intrinsic OER activity of the LaCoO₃ catalysts. The trend in the overpotential at a current density of 10 mA cm -2 recorded by linear sweep voltammetry (LSV) indicates differences in the electrochemical behavior based on the support electrode used in the study. The electrocatalytic activity varied depending on the support material, following the trend LCO/Ir> LCO/Ni >LCO/Pt >LCO/GC. In all cases, the coated electrode presented higher OER activity than the bare support electrodes, indicating the active participation of the catalytic LCO in the reaction. Spectroscopic techniques, such as FTIR and Raman, were employed to detect characteristic vibrational signature peaks, confirming catalyst coverage on the surface after drop casting. Further, for the interaction between the LaCO catalyst and the underlying substrates, FTIR spectroscopy was employed to probe surface functional groups and reaction intermediates. Characteristic bands related to H₂O formation and O₂ intermediates were observed in the 3600–2800 cm⁻¹ and 2000–1500 cm⁻¹ regions, respectively, and exhibited a cyclic behavior correlated with the applied potential, indicating dynamic surface reactions during OER. In addition, the peaks related to oxygenate intermediates on bare substrate increased on each cycle, which showed the irreversible growth of the oxide layer on the substrate. XPS analysis further validated the surface composition and chemical states, confirming the successful deposition of catalyst performance. To gain deeper insight into the charge transport characteristics at the catalyst–substrate interface, electrochemical impedance spectroscopy (EIS) was performed. The Nyquist plots revealed distinct differences in charge transfer resistance depending on the support material, and a similar trend was observed with respect to the activity at 10 mA cm -2 . Mott-Schottky analysis was performed to investigate the electronic properties, revealing differences in flat-band potential and charge carrier density between LaCoO₃ and the substrates. These findings emphasize the substrate's function in influencing the electronic conductivity and interfacial charge transfer efficiency, which are essential for optimal OER performance. References McCrory, C.C.L., et al., Benchmarking Heterogeneous Electrocatalysts for the Oxygen Evolution Reaction. Journal of the American Chemical Society, 2013. 135 (45): p. 16977-16987. Gerschel, P., et al., Determining materials for energy conversion across scales: The alkaline oxygen evolution reaction. Carbon Energy, 2024. 6 (12): p. e608.

Proton exchange membrane fuel cells (PEMFCs) convert chemical into electrical energy, making them promising for various applications. Understanding the interdependencies of processing steps along the catalyst coated membrane manufacturing process is crucial for optimizing performance. This study analyzes the entire process chain, including ink processing through magnetic stirring, ultrasonic sonication and wet impact milling, as well as the coating and characterization of the catalyst layer and its electrochemical performance. Findings indicate that particle size distribution, pore structure, and the detachment of platinum (Pt) from the Pt/carbon black (CB) catalyst significantly impact PEMFC performance. While magnetic stirring and ultrasonic sonication minimize Pt detachment, they lead to a broad particle size distribution and denser catalyst layers. Conversely, wet impact milling reduces Pt/CB particle size and promotes an optimal pore structure but also results in some Pt detachment. These results highlight the need to understand and optimize processing conditions to enhance PEMFC efficiency.

Improving the efficiency and stability of heterogeneous catalysts is essential for effectively utilizing peroxymonosulfate activation in industrial wastewater treatment. Perovskite ABO3 catalysts with high structural flexibility have gained considerable attention in the peroxymonosulfate activation for the removal of hazardous organic compounds from wastewater. However, there is still considerable potential for catalytic enhancement due to the ease of tailoring its composition and structure. Herein, we introduce a scalable method to synthesize LaCo0.2Mn0.8O3 with the aim of improving the catalytic performance. Interestingly, LaCo0.2Mn0.8O3 with abundant oxygen vacancies and improved dispersion stability exhibited enhanced catalytic degradation of carbamazepine compared to the LaMnO3 and LaCoO3 catalysts in the peroxymonosulfate activation system. The partial substitution of manganese by cobalt in LaMnO3 leading to the LaCo0.2Mn0.8O3+peroxymonosulfate system maintains a relatively high performance over repeated usage. Furthermore, the LaCo0.2Mn0.8O3 catalyst exhibited excellent catalytic performance and stability across a broad pH range (3-9). Electron paramagnetic resonance and radical quenching experiment tests demonstrated singlet oxygen (1O2) as the primary active species for carbamazepine degradation in the LaCo0.2Mn0.8O3+ peroxymonosulfate system, while free radicals, such as sulfate radicals (SO4 center dot-), hydroxyl radicals (center dot OH), and superoxide radicals (O2 center dot-), played a minor role in the carbamazepine removal. Taken together, this research provides significant insight into the effect of B-site substitution on the catalytic performance of perovskite catalysts.

Intensive research efforts have been devoted to remove trace amounts of toxic pollutants such as Ni(II) and Co(II) from water with the intention to provide clean fresh water to households. Iron-based adsorbents have attracted attention in the field of water purification because of their low cost, non-toxicity, and high availability in nature. However, due to their small volume, the recovery of the superparamagnetic iron-based adsorbents after the removal process in acceptably short times remains an unresolved research question. In this paper, we describe the fabrication of environmentally-friendly and superparamagnetic iron-oxide supraparticles optimized for the adsorption and removal of heavy metal ions and dyes from water with high recovery (within 20 s). The super-adsorbent iron-oxide supraparticles exhibited excellent removal efficiencies for Pb(II), Cr(III), Cd(II), Cu(II), Ni(II), Co(II), Li(I), and methylene blue (MB) with maximum adsorption capacities of 500, 446, 417, 366, 315, 294, 286, and 670 mg/g, respectively. Interestingly, the iron-oxide supraparticles with multicore structure revealed a higher saturation magnetization (72 Am2/kg) when compared to the as-synthesized iron-oxide nanoparticles (61 Am2/kg) that were used as starting material, facilitating fast recovery. The outstanding adsorption performance combined with the superparamagnetic properties and the high recovery demonstrates that low-cost iron-oxide supraparticles adsorbents can potentially be employed in water treatment and bioseparation.

In sodium-ion batteries (SIBs), TiO2or sodium titanates are discussed as cost-effective anode material. The use of ultrafine TiO2particles overcomes the effect of intrinsically low electronic and ionic conductivity that otherwise limits the electrochemical performance and thus its Na-ion storage capacity. Especially, TiO2nanoparticles integrated in a highly conductive, large surface-area, and stable graphene matrix can achieve an exceptional electrochemical rate performance, durability, and increase in capacity. We report the direct and scalable gas-phase synthesis of TiO2and graphene and their subsequent self-assembly to produce TiO2/graphene nanocomposites (TiO2/Gr). Transmission electron microscopy shows that the TiO2nanoparticles are uniformly distributed on the surface of the graphene nanosheets. TiO2/Gr nanocomposites with graphene loadings of 20 and 30 wt% were tested as anode in SIBs. With the outstanding electronic conductivity enhancement and a synergistic Na-ion storage effect at the interface of TiO2nanoparticles and graphene, nanocomposites with 30 wt% graphene exhibited particularly good electrochemical performance with a reversible capacity of 281 mAh g-1at 0.1 C, compared to pristine TiO2nanoparticles (155 mAh g-1). Moreover, the composite showed excellent high-rate performance of 158 mAh g-1at 20 C and a reversible capacity of 154 mAh g-1after 500 cycles at 10 C. Cyclic voltammetry showed that the Na-ion storage is dominated by surface and TiO2/Gr interface processes rather than slow, diffusion-controlled intercalation, explaining its outstanding rate performance. The synthesis route of these high-performing nanocomposites provides a highly promising strategy for the scalable production of advanced nanomaterials for SIBs.

In recent years, there has been a growing need for new renewable energy sources due to the rapid depletion of conventional energy sources and an escalating energy demand. Since environmental protection concerns are increasing, electrochemical processes are becoming increasingly essential [1]. Specifically, the focus has shifted towards storing energy in hydrogen and its subsequent conversion into on-demand electricity [2]. Here, hydrogen, generated via water electrolysis, serves as either an intermediary for generating energy carriers like liquid fuels or plays a key role as an energy carrier [3]. Despite significant efforts focused on enhancing electrolyzers for energy conversion, the progression towards practical application has encountered challenges stemming from differing catalyst development requisites in academic and industrial research. This study proposes a systematic approach for efficiently transitioning electrocatalysts from fundamental research to application readiness for alkaline oxygen evolution reactions. Herein, La 0.8 Sr 0.2 CoO 3 was chosen as a catalyst and compared with the benchmark material NiFe 2 O 4 . Initially, the La 0.8 Sr 0.2 CoO 3 catalyst was successfully synthesized by scalable spray-flame synthesis. Following this, various inks were formulated utilizing different binders (Nafion®, Naf; Sustainion®, Sus). The dispersion stability of La 0.8 Sr 0.2 CoO 3 and commercial NiFe 2 O 4 inks was investigated in the presence of Nafion and Sustainion using analytical centrifugation and transmittograms. Subsequently, these selected dispersions were applied onto nickel substrates via spray coating techniques, ensuring a homogeneous catalyst distribution. Finally, the La 0.8 Sr 0.2 CoO 3 and NiFe 2 O 4 catalysts were subjected to extensive electrochemical evaluations, including glassy carbon rotating disk electrode, scanning droplet cell (SDC), compression cell, flow cell, and zero-gap cell, to evaluate the material performance. SDC findings highlight the excellent uniformity in La 0.8 Sr 0.2 CoO 3 electrodes and NiFe 2 O 4 -Sustainion (standard deviation < 11%). However, the NiFe 2 O 4 -Sustainion film experienced delamination, exhibiting a standard deviation of 28%. SDC experiments offer advantages over various half-cell techniques by enabling the detection of any inhomogeneities or coating defects within the catalytic film. Additionally, complementary compression and flow cell experiments provide detailed information on the chemical and mechanical stress parameters resembling those in a full cell configuration. In assessing industrial applicability, the catalytic materials were undergone examination within a scalable full cell under industrial conditions (500 mA/cm² and 60 °C) utilizing a zero-gap cell setup. The observed trend in the full cell for the coated electrodes is as follows: La 0.8 Sr 0.2 CoO 3 -Naf > La 0.8 Sr 0.2 CoO 3 -Sus > NiFe 2 O 4 -Sus > NiFe 2 O 4 -Naf. These findings achieved through a well-structured coherent workflow, enhance our knowledge of the electrocatalytic system and offer essential insights for implementing novel materials in large-scale industrial applications. REFERENCES: [1] M.-S. Park, J. Kim, K.J. Kim, J.-W. Lee, J.H. Kim, Y. Yamauchi, Porous nanoarchitectures of spinel-type transition metal oxides for electrochemical energy storage systems, Phys. Chem. Chem. Phys. 17 (2015) 30963–30977. https://doi.org/10.1039/C5CP05936D. [2] J.R. Varcoe, P. Atanassov, D.R. Dekel, A.M. Herring, M.A. Hickner, P.A. Kohl, A.R. Kucernak, W.E. Mustain, K. Nijmeijer, K. Scott, T. Xu, L. Zhuang, Anion-exchange membranes in electrochemical energy systems, Energy Environ. Sci. 7 (2014) 3135–3191. https://doi.org/10.1039/C4EE01303D. [3] C. Van Pham, D. Escalera-López, K. Mayrhofer, S. Cherevko, S. Thiele, Essentials of High Performance Water Electrolyzers – From Catalyst Layer Materials to Electrode Engineering, Adv. Energy Mater. 11 (2021) 2101998. https://doi.org/https://doi.org/10.1002/aenm.202101998.

Trace organic pollutants including pharmaceuticals, industrial chemicals, pesticides, and personal care items pose considerable risks to the environment and human health due to their enduring nature, toxicity, and tendency to accumulate in biological systems [1,2]. In addressing this, sulfate radical-based advanced oxidation processes have emerged as highly promising advanced oxidation process methods for water and wastewater treatment in the past decade. Recently, transition metal-based perovskites like LaCoO 3 nanoparticles have gained attention in sulfate radical-based advanced oxidation processes due to their structural and compositional flexibility, strong electronic conductivity, and ability to create oxygen vacancies [3]. However, their practical application is hindered by metal leaching during wastewater treatment. Additionally, the robust and scalable synthesis of stable perovskite-based catalysts with large surface areas is crucial for their practical implementation in wastewater treatment but has been rarely achieved so far. In this study, we developed a cost-effective and scalable approach to produce novel LaCoO 3 /graphene nanocomposites for eliminating organic pollutants from wastewater. These newly developed catalysts demonstrated outstanding catalytic degradation (> 99%) of diclofenac, metoprolol, carbamazepine, and bisphenol A at a high concentration (40 mg/l) in less than 10 minutes in the peroxymonosulfate activation system, with a respective mineralization of 57%, 55%, 61%, and 62%. This improved performance compared to LaCoO 3 nanoparticles is attributed to the nanocomposite's abundant oxygen vacancies, synergistic effects between LaCoO 3 and graphene, and its larger surface area. More importantly, the LaCoO 3 /graphene nanocomposites showed good catalytic performance over a broad range of pH (from 3 to 11) and exhibited excellent reusability with consistent catalytic activity. Moreover, their catalytic efficacy remained largely unaffected in samples of drinking water and tap water, presenting high resistance to co-existing ions and NOM, proving the potential of LaCoO 3 /graphene materials for practical application in real wastewater treatment systems. The fabrication of LaCoO 3 /graphene composites effectively prevents cobalt leaching and increases the content of Co 2+ in the structure, resulting in significantly higher catalytic activity than that of pure LaCoO 3 . Experiments involving radical quenching and electron paramagnetic resonance revealed the involvement of both radical (SO 4 •– , • OH and O 2 •– ) and non-radical pathways ( 1 O 2 ) in pollutant degradation, with the 1 O 2 radical playing a predominant role in the oxidation of the pollutant. The relative contributions of • OH, SO 4 •– , and 1 O 2 /O 2 •– were determined to be 13.4%, 32.6%, and 54% for bisphenol A removal, respectively. Overall, our findings demonstrate the potential utilization of the LaCoO 3 /graphene system for peroxymonosulfate activation in environmental remediation. REFERENCES: [1] A. Asghar, M. Hammad, K. Kerpen, F. Niemann, A.K. Al-Kamal, D. Segets, H. Wiggers, T.C. Schmidt, Ozonation of carbamazepine in the presence of sulfur-dopped graphene: Effect of process parameters and formation of main transformation products, Sci. Total Environ. 864 (2023) 161079. https://doi.org/https://doi.org/10.1016/j.scitotenv.2022.161079. [2] M. Hammad, P. Fortugno, S. Hardt, C. Kim, S. Salamon, T.C. Schmidt, H. Wende, C. Schulz, H. Wiggers, Large-scale synthesis of iron oxide/graphene hybrid materials as highly efficient photo-Fenton catalyst for water remediation, Environ. Technol. Innov. 21 (2021) 101239. https://doi.org/https://doi.org/10.1016/j.eti.2020.101239. [3] M. Hammad, B. Alkan, A.K. Al-kamal, C. Kim, M.Y. Ali, S. Angel, H.T.A. Wiedemann, D. Klippert, T.C. Schmidt, C.W.M. Kay, H. Wiggers, Enhanced heterogeneous activation of peroxymonosulfate by Ruddlesden-Popper-type La2CoO4+δ nanoparticles for bisphenol A degradation, Chem. Eng. J. 429 (2022) 131447. https://doi.org/https://doi.org/10.1016/j.cej.2021.131447.

Despite considerable efforts to develop electrolyzers for energy conversion, progress has been hindered during the implementation stage by different catalyst development requirements in academic and industrial research. Herein, a coherent workflow for the efficient transition of electrocatalysts from basic research to application readiness for the alkaline oxygen evolution reaction is proposed. To demonstrate this research approach, La0.8Sr0.2CoO3 is selected as a catalyst, and its electrocatalytic performance is compared with that of the benchmark material NiFe2O4. The La0.8Sr0.2CoO3 catalyst with the desired dispersity is successfully synthesized by scalable spray-flame synthesis. Subsequently, inks are formulated using different binders (Nafion®, Naf; Sustainion®, Sus), and nickel substrates are spray coated, ensuring a homogeneous catalyst distribution. Extensive electrochemical evaluations, including several scale-bridging techniques, highlight the efficiency of the La0.8Sr0.2CoO3 catalyst. Experiments using the scanning droplet cell (SDC) indicate good lateral homogeneity for La0.8Sr0.2CoO3 electrodes and NiFe2O4-Sus, while the NiFe2O4-Naf film suffers from delamination. Among the various half-cell techniques, SDC proves to be a valuable tool to quickly check whether a catalyst layer is suitable for full-cell-level testing and will be used for the fast-tracking of catalysts in the future. Complementary compression and flow cell experiments provide valuable information on the electrodes’ behavior upon exposure to chemical and mechanical stress. Finally, parameters and conditions simulating industrial settings are applied using a zero-gap cell. Findings from various research fields across different scales obtained based on the developed coherent workflow contribute to a better understanding of the electrocatalytic system at the early stages of development and provide important insights for the evaluation of novel materials that are to be used in large-scale industrial applications.

In this study, acid-treated graphene (Gr-COOH) catalyst was synthesized using a microwave plasma reactor, and its performance in different combinations of ozone and ozone activated peroxymonosulfate (O3, O3 + Gr-COOH, O3 + PMS, and O3 + PMS + Gr-COOH) was kinetically evaluated. The yields of SO & BULL;-4 and HO & BULL; were quantified based on ozone consumption. Among the different operating parameters, the effect of pH (4  8) was particularly considered. The results showed that heterocatalytic ozone-based activation of peroxymonosulfate performed efficiently at neutral and alkaline conditions. The first-order rate constants for O3 decomposition in O3 +PMS +Gr-COOH (1.2 x 10  2s  1) was higher than O3 +PMS (8.5 x 10  3s  1) and O3 (2 x 10  4s  1) by a factor of 1 and 2 respectively. The radical yields were positively associated with pH. Higher pH values showed a notable increase in radical yields (& eta;), with the maximum value of & eta;Total (0.88) and & eta;HO & BULL; (0.53) obtained at pH 8 while & eta;SO & BULL;4 showed maxima (0.46) at pH 7. This implies that at higher pH i.e., 8, HO & BULL; was the dominant reactive specie, which could be due to the presence of higher concentration of HO  and transformation of SO & BULL;-4 into HO & BULL;. Furthermore, the synergistic effects of the oxidative processes were tested considering atrazine (ATZ, 1 & mu;M) and nitrobenzene (NB, 1 & mu;M) as probe compounds. The best performance was obtained with O3 +PMS +Gr-COOH process, reaching 96% and 81% of ATZ and NB removal respectively. The suppressive effects of inorganic ions and natural organic matter (NOM) on the degradation efficiency of ATZ and NB were also lower for O3 +PMS +Gr-COOH process. These results confirmed that acid-treated graphene (Gr-COOH) catalyst in combination with ozone activated peroxymonosulfate could be an efficient and promising alternative oxidative process.