Mesoporous architecture confinement engineering has become an effective approach to address major limitations of single-atom catalysts (SACs) and integrated CO2 capture-conversion systems. These techniques may provide enhanced control of the spatial distribution, local microenvironment and pore size to attain high activity, selectivity and permanence in photocatalytic and electrocatalytic CO2 reduction. The recent trends in confinement mechanisms that have been highlighted in the present paper include two step space-confinement pyrolysis, hierarchical porosity in MOFs, single-micelle assembly and defect engineering. These methods enable the fabrication of well-defined nanoreactors, allowing synergistic reactions between photoactive and catalytic species, cascade reactions, tremendous charge separation and carrier lifetimes. Mesoporous supports with both single-atom and dual-atom sites are given special consideration, where tunable coordination environments and dynamic structural evolution under operating conditions play critical roles in dictating selectivity to high value C1 or C2 products at low over potentials. When mesoporous SAC systems are compared with traditional amine-based sorbents and nanoparticle catalysts, it can be seen that mesoporous materials have clear advantages in regard to regeneration energy, humidity resistance, cycling stability, and combined capture-conversion efficiency. Physical confinement and electronic modulation (with a state-of-the-art inverse design and Bayesian optimization) offers the paradigm of scalable, energy-efficient use of CO2. Finally, low active-site density, long-term stability, and industrial translation have been identified as key issues and a roadmap to the future that incorporates the development of hierarchical multi-scale porous structures to host both SACs, full CCUS loops with renewables, and technologies that produce negative emissions using the sun as the power source have been discussed.
Photovoltaic (PV) system experiences the problem of rise in internal temperature and can be overcome by integrating phase change materials (PCMs). However, PCM incorporated into PV systems demonstrates insufficient thermal conductivity, resulting in diminished heat transfer within the system. The primary aim of this research is to experimentally assess the electrical and thermal performance of PV systems employing both passive and active methodologies by integrating innovative hybrid particle (bamboo shell and expanded graphite) enhanced phase change materials (HePCM). The results implied that 0.5 weight% of bio-waste derived bamboo shell particles and 1 weight% of low-cost expanded graphite particles in hybrid combination integrated with PCM exhibited an enhancement of 81.05% in thermal conductivity. Besides, composite approximately maintained 197 Jg-1 latent heat of enthalpy as compared to 192 Jg-1 of base PCM and 84.97% decrease in photo-transmittance along with thermal stability up to 1000 thermal cycles. Further, maximum electrical efficiency was found 12.3 % and 12.6 % for PV-integrated PCM and HePCM passive systems in comparison to 11.94 % for simple PV. Similarly, for active systems, maximum electrical efficiency was noticed to be 13 and 13.3% for PVT integrated PCM and HePCM systems, respectively. Furthermore, maximum thermal efficiency was achieved to be 75.1, 78.4, and 79.6% for PVT, PVT-PCM, and PVT-HePCM systems at a 0.3 LPM flow rate and irradiation of 500 Wm-2.
Metal-organic frameworks (MOFs) have emerged as promising fillers for enhancing polymer electrolyte membranes in fuel cell applications. In this study, sulfonated poly(vinylidene fluoride-co-hexafluoropropylene)/cellulose acetate (SPvF/CA) composite membranes incorporating sulfonated ZIF-8 (SZ) were successfully fabricated via solution casting for direct methanol fuel cells (DMFCs). Structural, morphological, and thermal properties were comprehensively characterized by FTIR, XRD, SEM/EDS, TEM, AFM, and TGA, confirming successful membrane fabrication and uniform SZ dispersion. The optimized SPvFC30/SZ5 membrane exhibited improved proton conductivity of 9.35×10-3 S cm-1, representing a remarkable enhancement over pristine CA (0.08×10-3 S cm-1), together with improved hydrophilicity, water uptake, and oxidative stability. In addition, methanol permeability was reduced to 1.95×10-7 cm2 s-1, approximately 11-fold lower than Nafion®117, resulting in a 7.5-fold increase in electrochemical selectivity. Single-cell testing delivered a maximum power density of 75.58 mW cm-2 at 80 °C, approaching that of Nafion®117 (∼ 80 mW cm-2). These findings demonstrate that the developed SPvFC30/SZ5 membrane is a cost-effective and high-performance proton exchange membrane for low-temperature DMFC applications.
Composite materials based on nickel sulphide (Ni3S2) and selenide (Ni3Se2) with nanowire morphology were synthesised on Ni foam, modified by low-temperature hydrothermal treatment with or without Fe incorporation, and evaluated as electrocatalysts for the 5-hydroxymethylfurfural oxidation reaction (HMFOR) to 2,5-furandicarboxylic acid (FDCA), a key monomer for the production of bio-based plastics. The nickel selenide-based electrocatalysts outperformed their sulphide counterparts. Particularly, the selenide composite prepared by hydrothermal treatment at 40 °C without introducing Fe (H2O-Ni3Se2/Ni-foam-40) achieved nearly complete HMF conversion within 90 min at 1.6 V vs RHE (1.0 M KOH, room temperature), with 96 % yield and 94 % Faradaic efficiency towards FDCA. Under identical conditions, the benchmark Ni foam showed only 36 % HMF conversion and 7 % FDCA yield. Fe incorporation in the electrocatalyst was found to be detrimental for the HMFOR selectivity as it promoted the competing oxygen evolution reaction. In-situ Raman spectroscopy allowed identifying NiOOH as the key catalytic intermediate operating through an indirect mechanism in which HMF is oxidised by Ni(III) species that are continuously regenerated at the applied potential. The promising HMFOR performance shown by H2O-Ni3Se2/Ni-foam-40 was achieved with a much higher initial HMF concentration (100 mM) than generally used, bringing this electrochemical route closer to application.
Flexible multi-functional sensors are highly desirable for health monitoring and human-computer interaction due to their adaptability and mechanical flexibility. However, materials with tunable properties for the sensitive response and flexibility of the sensors are in highly shortage. To relive this issue, we propose a novel strategy that adjusts crystallinity (Xc) to enhance the lateral deformation (LD) of Eucommia ulmoides rubber (EUR) under compression, thereby improving the sensor performance. We successfully prepared a series of EUR elastomer (EURE) composites with controllable Xc by destroying the internal crystalline structure of EUR via epoxidation, followed by blending and vulcanization with varying amounts of EUR. The results show that the LD capability of EURE composites under compression significantly increases as Xc decreases. One-At-a-Time partial sensitivity analysis (OAT) reveals that Young's modulus (E) is the dominant factor governing the change in LD. Subsequently, graphite was introduced into the EURE composite to fabricate sensor. The sensor exhibits a pressure sensitivity of 2.28% kPa-1 in the range of 0-12 kPa, a rapid response time of 0.63 s, robust cycling stability, and a temperature coefficient of resistance (TCR) of 0.57% °C-1 over 15-55 °C. Successfully monitoring the temperature fluctuations and human motions in excellent electrical responses confirms its promising potential for fabricating wearable sensors.
Carbon reinforced plastics, can contribute to climate change mitigation due to their excellent mechanical properties and light weight. Petroleum derived polyacrylonitrile (PAN) is the most common precursor material for carbon fibres, with 90 % of the fibres being produced in a wet spinning process. Lignin offers a renewable, sustainable and cost-effective alternative to PAN as it is obtained as a by-product of paper production and the second most common biopolymer in the world. Lignosulfonate, a technical lignin, has promising spinning properties such as thermosetting behaviour. Also, its higher molecular weight, compared to other technical lignins, leads to higher viscosity in solution. In this work, ammonium lignosulfonate and polyvinyl alcohol were dissolved in deionised water and wet-spun into continuous fibres using a custom-designed and programmed system. Acetone was used as a coagulation agent. Different ratios of lignosulfonate and polyvinyl alcohol with up to 90 % lignosulfonate content were tested and their influence on fibre production and chemical properties analysed. The fibres were carbonised directly without prior stabilisation at 10 °C/min to 1000 °C with a holding time of 30 min at 1000 °C. Regardless of the ratio between lignosulfonate and polyvinyl alcohol, carbon fibres with a diameter of 7 μm and a maximum carbon yield of 37.4 % could be achieved. A maximum tensile modulus of 38 ± 5 GPa and a maximum tensile strength of 468 ± 110 MPa were observed.
As a relatively new member of the nanocarbon family, carbon dots (CDs) have attracted significant scientific interest over the past two decades due to their unique attributes, including tunable luminescence, facile functionalization, and excellent biocompatibility. The synthesis of CDs from biomass has emerged as an appealing strategy, not only for its sustainability but also for the inherent heteroatom doping and surface functionalities imparted by the precursor materials. However, raw biomass is often considered chemically impure and highly variable, which can limit reproducibility and control over the physicochemical properties of resulting CDs. Refinement of biomass into well-defined constituent molecules, such as lignin, which is rich in aromatic structures, offers a promising pathway toward the production of high-quality CDs. For successful commercial translation of CDs in areas such as device fabrication, sensing, and biomedical applications, reproducible and well-defined synthetic protocols that enable precise control over CD properties are essential. With this objective, the present review summarizes lignin-derived CD synthesis methodologies and systematically examines their influence on optical properties, considering their diverse origins and processing methods. This review aims to serve as a practical roadmap for researchers, facilitating the rational selection of biomass sources and synthesis strategies for designing high-performance CD-based materials with tailored properties while maintaining a strong emphasis on sustainability.
In this study we introduce a sustainable route to the green synthesis of zinc tetrahydroxide bis nitrate (Zn3(OH)4(NO3)2) nanoparticle additives using waste rapeseed oil as a synthesis medium. A solvent-free, low-temperature synthesis route starting at 110°C was developed yielding Zn3(OH)4(NO3)2 with temperature-dependent structural and morphological evolution as confirmed by XRD, FTIR, NMR, SEM, and TEM analyses. The nanoparticles synthesized at 130°C presented the smallest crystallite size, balanced organic–inorganic interactions, and a platelet-like morphology. Stability tests of these nanoparticles blended in Jet A-1 aviation fuel demonstrated that all formulations remained colloidal for at least 48 h, with the sample synthesized at 130°C retaining long-term stability exceeding four months. The measured physicochemical properties of Jet A-1 fuel containing nanoadditives remained within the ASTM D1655 specification limits for the parameters evaluated in this study. Emission tests confirmed a reduction in NOx, NO and NO2 for the fuel blends containing nanoadditive synthesized at 130°C, with a reduction of NO2 emissions of 18% under combustion test conditions on a real airplane turbo motor. These results demonstrate that green-synthesized Zn3(OH)4(NO3)2 nanoadditives offer a practical, sustainable pathway to cleaner jet fuel emission and can serve as a complementary strategy alongside sustainable aviation fuels in advancing the aviation sector's net-zero initiatives.
The increasing concentrations of various antibiotics and textile dyes in aquatic environments present significant risks to both aquatic and human health. To address this issue, a CuWO4@TiO2 core-shell nano-adsorbent was synthesized by a green and sustainable hydrothermal process and applied to efficiently remove ciprofloxacin (CIP) antibiotic and methylene blue (MB) dye molecules from wastewater. A variety of characterization instruments were utilized to identify the physicochemical structure of the synthesized nano-adsorbent. Comprehensive characterizations using XRD, FTIR, FE-SEM, TEM, XPS, and BET studies have provided concrete evidence of the development of a TiO2 -coated CuWO4 core-shell-structured adsorbent. Characterizations such as XRD and FTIR have shown the existence of amorphous CuWO4 and TiO2 phases with chemical bonding at the interface between CuWO4 and TiO2. FE-SEM and TEM images have clearly demonstrated the morphological difference in which TiO2 forms an even shell over the CuWO4 core. XPS results indicate that the outer shell of TiO2 is enriched in Ti, thus showing that the coating was complete. The Box-Behnken design (BBD) optimized methodology was utilized to optimize the operational variables such as dosages of nano-adsorbent, dosages of CIP, solution pH, and treatment time. The findings showed nearly complete CIP (99.0 ± 0.3%) adsorption at a CIP concentration of 10 mg/L, a dosage of adsorbent of 340 mg/L, and a treatment time of 40 minutes at neutral pH (7.0). The same optimized dosages were also tested for MB dye adsorption, and complete dye adsorption (100 % of MB) was achieved at only five (5) minutes of treatment. The adsorption was found to follow pseudo-second order, which is indicative of chemisorption as the rate-controlling step. The isotherm modeling results showed that the Langmuir equation fitted best with R2 values of > 0.99, exhibiting maximum monolayer adsorption capacities (qm) of 113.4 ± 6.4 mg/g for CIP at 30°C, after which the capacities decreased with an increase in temperature, indicating exothermic adsorption. The thermodynamic evaluation confirmed that the process was spontaneous (ΔG0 = -4.56 to -4.06 kJ/mol), exothermic (ΔH0 = -12.18 kJ/mol) and accompanied by reduced interfacial randomness (ΔS° = -25.15 J/mol·K). This supports the view that electrostatic attraction, hydrogen bonding, surface complexation, and π-π stacking facilitate the adsorption of CIP and MB via chemisorption. Its reusability over five cycles confirmed its structural integrity and practical applicability. It demonstrates highly efficient and reusable broad-spectrum efficacy in removing mixed emerging contaminants, showing potential for scalable application in treating wastewater from the pharmaceutical and textile industries.
The rapid development of lithium iron phosphate (LiFePO4, LFP) batteries and the increasing demand for sustainable hydrogen production provide a unique opportunity to re-establish the link of material lifecycles among energy systems. Traditional LFP recycling primarily involves elemental recovery, often deconstructing the chemically embedded Fe−O−P framework that gives it its structural identity. In this review, we propose a conceptual framework for the functional upcycling of spent LiFePO4 as a chloride-selective catalytic platform for seawater electrolysis. We propose a unifying mechanism of phosphate shielding, in which lattice-anchored electrostatic structuring and inductive electronic modulation of Fe centers work synergistically to suppress chlorine evolution while promoting oxygen evolution in saline environments. Structural features generated during battery operation, including lithium vacancies and defect-mediated heterogeneity, further condition the surface for selective catalysis. Unlike conventional oxide catalysts, which are susceptible to chloride-induced degradation and rely on dynamic reconstruction, the rigid polyanionic framework of LFP is inherently resistant to corrosion and exhibits minimal surface change. Upcycling LFP couples charge-transfer engineering with lattice-structure preservation to bridge end-of-life battery management with hydrogen production from seawater, demonstrating how structural stability can act as a catalytic asset in a circular energy context.
Silicon oxycarbide (SiOC), a polymer-derived ceramic characterized by high theoretical capacity, small volume expansion, and superior electro-chemo-mechanical stability, has attracted considerable attention as a particularly promising alternative to Si-based and carbonaceous anodes for next-generation lithium-ion batteries (LIBs). However, its low effective capacity, inferior initial Coulombic efficiency, and poor electrical conductivity pose significant challenges for practical applications. Notably, by integrating composition effect and design flexibility, SiOC-based composites provide a revolutionary new paradigm for overcoming the performance bottlenecks and practicality problems of SiOC. The past nearly two decades has witnessed numerous elaborately designed and ingeniously engineered SiOC-based composites for anodes in LIBs. In this review, the fundamental design concept of advanced SiOC-based composite anodes with boosted lithium storage properties is first introduced. Then, we systematically classify and summarize the latest research progress in SiOC-based composite anodes from the perspective of materials system, dividing them into SiOC/C composites, SiOC/Si composites, and SiOC/metal composites, with a focused discussion on their design schemes, preparation approaches, and lithium storage performance. Finally, the remaining key challenges are outlined, and future research agenda is proposed. We believe that this review provides an actionable roadmap for unlocking the full potential of SiOC-based composite anodes in the next-generation high-energy LIBs.
The global transition toward low-carbon urban infrastructure has positioned geopolymers as promising alternative binders for the built environment. Their three-dimensional aluminosilicate framework and tunable pore-solution environment offer opportunities for structure-integrated thermoelectric functions. This review synthesizes geopolymer-based thermoelectric materials by integrating transport mechanisms, materials design strategies, and device integration into a unified framework. The review examines how pore-solution ion transport, binder microstructure, composite pathways, and electrode-related interfacial processes collectively shape the apparent thermoelectric response. Strategies for modulating the apparent Seebeck coefficient, effective electrical conductivity, and thermal conductivity, from ionic regulation to microstructural and composite engineering, are critically evaluated in light of intrinsic trade-offs. Device-level demonstrations and integration requirements are further examined, including electrode-binder interfaces, moisture-regulated packaging, construction compatibility, and application-oriented evaluation for low-power functions. Sustainability considerations are discussed in relation to module-level carbon- and energy-burden screening, industrial by-product precursors, and reduced reliance on critical or supply-constrained thermoelectric elements. Finally, future directions are outlined to shift from material-centric optimization toward stable, low-power thermoelectric components designed for infrastructure-integrated sensing and localized energy harvesting.
Current collectors for lithium-metal batteries must control both initial Li nucleation and the formation and evolution of the reconstructed interface established during first lithiation. Here, phase-controlled Cu-Sn interphases were fabricated on ultrathin Cu current collectors by a scalable rolling-annealing route, enabling a systematic transition from a Sn-rich surface layer to mixed Cu6Sn5/Cu3Sn regions and Cu3Sn-rich frameworks. The interphase constitution changed the first-lithiation pathway and suppressed the apparent Li nucleation overpotential from ∼65 mV on bare Cu to near-zero values on CS_280, although alloying reactions and Li nucleation may partially overlap in Cu3Sn-rich samples. Combined microscopy, diffraction, spectroscopy, impedance, and cycling results indicate that Cu3Sn-rich interphases are associated with reduced protrusive Li growth and with thinner, denser Li-containing regions within a reconstructed interfacial zone. Because Li is not directly detected by EDS, this assignment is treated as an interpretation rather than direct Li mapping. In anode-free full cells (N/P = 0), moderately alloyed CS_150-CS_280 electrodes retained approximately 40–50% capacity after 100 cycles and approximately 25–30% after 200 cycles, exceeding bare Cu. Under Li-excess conditions (N/P = 3), the more Cu-rich CS_350 retained ∼80% after 100 cycles. The central contribution of this work is to establish a scalable, phase-controlled metallurgical interphase platform and demonstrate that the initial Cu–Sn phase constitution governs first-lithiation reconstruction, while the balance between reconstruction-induced Li consumption and interfacial stability determines the optimum current collector under different Li inventories.
Per- and polyfluoroalkyl substances (PFAS) have long enabled high-performance surface and barrier materials due to their exceptional chemical stability, durability, and ultra-low surface energy arising from the carbon–fluorine bond. However, their environmental persistence, global distribution, and associations with adverse health outcomes have accelerated regulatory action and intensified the search for safer alternatives. Replacing PFAS while maintaining critical functionalities, such as water and oil repellency, chemical resistance, and long-term durability, remains a central challenge in materials science. This review integrates regulatory drivers with structure -property relationships to critically evaluate emerging fluorine-free strategies for coatings and barrier applications. We examine key classes of non-fluorinated polymers, bio-based materials, and hybrid composite systems, highlighting how performance is achieved through complementary mechanisms including surface energy modulation, pore sealing, diffusion tortuosity introduced by high-aspect-ratio fillers, hierarchical surface structuring, and composite architectures. Rather than relying solely on ultralow surface energy, many PFAS-free systems achieve functional performance through geometry-enabled transport control and synergistic material design. Comparative analysis reveals that while no single fluorine-free material universally replicates PFAS performance, application-specific designs can deliver competitive water and oil resistance, barrier properties, and mechanical integrity. Remaining challenges include durability under real-world conditions, scalability within existing manufacturing infrastructure, and comprehensive life-cycle and toxicological assessment to avoid regrettable substitutions. By synthesizing advances across polymer chemistry, surface engineering, and sustainable materials design, this review outlines mechanistically informed pathways toward scalable, high-performance, and environmentally responsible alternatives to PFAS for next-generation surface and barrier technologies.
Carbon fiber–reinforced plastics (CFRPs) provide outstanding mechanical performance but face critical sustainability challenges due to the irreversible crosslinked nature of conventional thermoset matrices. Herein, we report a mechanically robust sulfur-rich terpolymer matrix synthesized via inverse vulcanization of industrial waste elemental sulfur with tricyclopentadiene (TCPD) and allyl glycidyl ether (AGE) crosslinkers, designed for sustainable and multifunctional CFRP systems with improved end-of-life management. By systematically tuning the relative contributions of TCPD- and AGE-derived network structures, the thermomechanical properties of the terpolymer were precisely controlled, yielding a composition that exhibits a balanced combination of mechanical robustness and thermal stability. Leveraging the dynamic nature of polysulfide linkages, the terpolymer enables solvent-free powder processing into high-performance CFRPs via simple hot pressing, effectively overcoming the viscosity control and scalability limitations of conventional prepolymer casting methods. The resulting CFRPs show uniform fiber impregnation and excellent mechanical properties, while enabling efficient carbon fiber recovery through thiol–polysulfide exchange–mediated chemical degradation. The recovered carbon fibers can be directly reused to refabricate CFRPs using stored powders without loss of mechanical performance. In addition, the composites demonstrate multifunctional capabilities, including weldability, repairability, shape reconfiguration, and thermally programmable shape memory behavior, which are demonstrated through a three-dimensional dump trailer–mimetic structure. Overall, this work presents a sustainability-oriented strategy for recyclable and multifunctional CFRP systems based on sulfur-rich polymer matrices.
Coordination polymers based on ethenetetrathiolate ligands are promising materials for developing innovative thermoelectric technologies as they combine intrinsic electrical conductivity, favorable Seebeck coefficients, and potentially reduced reliance on scarce and critical raw materials. However, their integration into planar and flexible modules remains constrained by processability and device-engineering challenges. Here, we investigate complementary p-type poly[Kx(Cuett)] and n-type poly[Kx(Niett)], through a combined experimental and theoretical study aimed at developing thermoelectric modules. The two polymers are solution-processed without additives or post-treatments, enabling their direct deposition as thin films. Films exhibit suitable electrical conductivity and complementary thermoelectric responses. Molecular modeling links the charge-transport behavior to the metal-dependent electronic structure and reproduces the experimental Seebeck coefficients. Their complementary thermoelectric behavior, combined with solution processability, enable integration into planar p-n modules on different substrates, including glass, flexible PET, and low-cost paper. Thermoelectric modules exhibit Seebeck coefficients of 150-230 μV/K in the 20-60 °C range, consistent with the additive contribution of the individual legs. Additionally, the unencapsulated modules show remarkable mechanical and long-term ambient stability. These findings demonstrate that coordination polymers based on ethenetetrathiolate ligands, combining facile synthesis with additive-free, low-temperature solution processing, offer a promising platform for the development of versatile and more sustainable thermoelectric devices for low-grade energy conversion.
The practical application of lithium metal batteries (LMBs) is still severely limited by safety concerns such as lithium dendrite growth and the flammability of conventional electrolytes. To address these critical issues, this study proposes cooperative dual-salt electrolytes utilizing lithium trifluoromethanesulfonate (LiOTf) and lithium bis(oxalato)borate (LiBOB) in a non-flammable trimethyl phosphate (TMP) solvent for high-stability and safety LMBs. The optimized Li[OTf/BOB]-55 electrolyte significantly reconstructs the Li+ primary solvation shell. This unique structural modification promotes the preferential reductive decomposition of LiBOB at higher potentials and operates synergistically with LiOTf decomposition products, thereby forming a robust dual-layer inorganic–organic composite solid electrolyte interphase (SEI) on the lithium metal anode. The inner layer is enriched with inorganic species such as Li2CO3 and LixBOy that facilitate ionic conduction, while the outer elastic organic polymeric layer imparts mechanical toughness. This highly stable and elastic SEI effectively suppresses the continuous consumption of the TMP solvent and blocks lithium dendrite propagation at the microscopic level. The optimally proportioned electrolyte endows the batteries with outstanding electrochemical performance: Li//Li symmetric cells achieve an ultra-long stable cycle life of over 1700 h and tolerate a critical current density of up to 1.25 mA cm−2, while Li//Cu cells deliver a high average coulombic efficiency of 92.27%. In application evaluations, Li//LiMn2O4 cells utilizing this electrolyte realize a remarkably long lifespan of 1600 cycles at a high rate of 500 mA g−1. Furthermore, the system exhibits excellent temperature adaptability and interfacial stability across a wide temperature range from −20 °C to 60 °C. The proposed non-flammable dual-salt electrolyte design, enabled by solvation structure engineering, offers a highly practical and promising strategy for the development of next-generation safe LMBs.
CaCu3Ti4O12 (CCTO) double-oxide perovskites were synthesized through a molten-salt method using NaCl (Na-CCTO) and LiCl (Li-CCTO) and subsequently employed as photo-electrodes for the nitrogen reduction reaction (N2RR). The effect of the different salts on defects, microstructure, and photo-electrochemical behaviour was systematically investigated. The obtained results show that the two synthetic routes lead to distinct morphologies and Eg values (1.9-2.3 eV), with a higher defect concentration observed in the Li-CCTO system. Photo-electrodes were deposited by screen-printing and their properties were evaluated by EIS analyses, Mott–Schottky method, cyclic and linear sweep voltammetry under different illumination conditions. In this case, both systems exhibit photoactivity under illumination, displaying different charges movement behaviours in function of different salts used. Li-CCTO generates the highest photocurrent equal to 0.3 mA cm−2 at −0.8V vs Ag/AgCl with NH3 yields between 9 and 10 μg h−1 cm−2 and Faradaic efficiency of 23% at −0.4V vs NHE, whereas Na-CCTO exhibits comparable photocurrent and Faradaic efficiency for NH3 of 28% at the same low potential applied. In this work, CCTO was used for the first time to N2RR by PEC, opening the way to this material also in this new energy application.
Noble-metal plasmonic photothermal catalysis has become a viable method to enhance catalytic behaviour owing to the synergistic nature of photonic and localized thermal excitation. In the present review of the status of the noble plasmonic metal photothermal catalytic systems, the developments are summarized in detail with a specific focus on the structural design and mechanistic understanding. Initially, the theory of plasmonic photothermal catalysis, including localized surface plasmon resonance (LSPR), hot carrier generation and transfer, and near-field electromagnetic enhancement, which are all combinations of light harvesting and catalytic behaviours, is also addressed. The optical behaviour dependence on morphology-dependent parameters, such as particle size, shape, and structural symmetry, and catalytic efficiency is critically analyzed. In addition, the importance of the creation of heterojunctions between noble metals and semiconductor materials is also explained for the promotion of charge separation, the intensity of interactions at the interface, and the stability of catalysts. Systematic discussions on these catalytic systems have been utilized in energy conversion and environmental remediation in the form of the production of solar fuels and pollutant degradation. Finally, there are issues that exist concerning mechanistic insight, long-term stability and scalability, which are also articulated and provide insights into the rationalize for future development of better plasmonic photothermal catalyst.
According to the waste management concept, the biomass and spent Li-ion batteries have been valorized to synthesize sustainable supercapacitor electrodes. The peanut shell-derived biochar, along with recovered spent graphite (RSG) from battery waste, upon chemical activation with KOH, yielded a microporous, high-surface-area composite (AC/RSG) with efficient charge transport. It reveals a specific capacitance of 376 F/g at 10 mV/s (and 197 F/g at 0.4 A/g) in a three-electrode cell set-up using 1 M KOH electrolyte. The reference samples are porous activated carbon (AC) and another composite containing few-layer graphene (FLG) from commercial expanded graphite. The addition of RSG and FLG to activated carbon increases capacitance by approximately 70% and 50%, with significant stability at extreme conditions (high current density and potential sweep rate), thus maintaining the energy density with power density increase. The capacitance retention increases from 48% (and 49%) for porous carbon to 89% (and 83%) and 81% (and 78%) for AC/RSG (and AC/FLG) composites, at 17.7 A/g (and 200 mV/s). The structural features of the three materials, particularly of the composites, impacting the storage behavior, are investigated with help of auxiliary samples (KOH-activated RSG and FLG). The cyclic stability test for the best-performing composite (AC/RSG) revealed 94% capacitance retention and 99.6% Coulombic efficiency over 5000 cycles at 4.4 A/g. Beside enhanced conductivity, the electrochemical analysis revealed a significant benefic impact of diffusion and charge transfer in the composites. Additionally, conductive carbon black (CB) additive is successfully replaced by RSG. This study paves the way for improving the electrochemical performance of traditional biomass-derived activated carbons by the incorporation of graphite waste.
