In the heterogeneous photo-Fenton-like system, enhanced separation and migration of photogenerated charge carriers can further accelerate the redox cycle of metal ions and promote both H2O2 activation and the generation of reactive oxygen species (ROS). In this work, copper-loaded carbon nitride with nitrogen vacancies (Cu-Nv-CN) was synthesized. Cu-Nv-CN exhibits outstanding heterogeneous photo-Fenton-like activity, 94.0% of tetracycline (TCH) is eliminated within 50 min in the presence of 10 mM H2O2, and the corresponding degradation rate constant reached 0.0522 min-1. Surface photovoltage and femtosecond transient absorption (TA) spectroscopy measurements revealed that Cu sites act as effective electron trapping centers. Furthermore, the introduction of Nv drives the rapid migration of photogenerated electrons to the Cu sites. The synergistic interplay between these two factors significantly improves the utilization efficiency of photogenerated charge carriers. The photo-Fenton-like pollutant degradation mechanism of Cu-Nv-CN was systematically elucidated by combining radical trapping experiments, electron paramagnetic resonance (EPR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) measurements. This study proposes a viable strategy for boosting the catalytic activity of graphitic carbon nitride-based photocatalysts in advanced photo-Fenton-like systems.

By doping metal Mn into the traditional OER catalyst Co-MOF, a bimetallic MOF is constructed to improve the unsatisfactory discharge performance of Co-MOF. The Co/Mn ratio is optimized to achieve the dual catalytic effect. After decorating Co5Mn12-MOF onto Ti-Fe2O3 nanorods, the charge transfer resistance and recombination rate of photogenerated carriers are significantly suppressed, with the charge separation efficiency increasing from 34.2% to 67.6%. A built-in electric field is formed between the two components, through which photo-generated holes are driven to the electrolyte interface. Consequently, the photocurrent density at 1.23 V vs. RHE is enhanced by approximately 6.7 times, achieving a remarkable improvement in OER performance. The charging potential at 0.1 mA cm-2 decreases from 2.08 V under dark conditions to 1.19 V under illumination. Owing to this dual catalytic function, the round-trip energy efficiency of Co5Mn12-MOF/Ti-Fe2O3 is improved to 84.9%.

A series of sodium-ion battery anode materials are synthesized from discarded orange peels by adjusting the carbonization temperature. The hard carbon obtained at 1300 degrees C shows the smallest specific surface area-contributing to a high initial Coulombic efficiency-and the largest average pore size, facilitating sodiumion diffusion. At 60 mA g- 1, it delivers a reversible capacity of 377.3 mAh g- 1 with an initial Coulombic efficiency of 75.2%. Further activation with NH4Cl via a two-step hydrothermal-carbonization process improves performance. At a precursor/NH4Cl mass ratio of 1:2, the activated material retains 80.53% capacity after 400 cycles at 60 mA g- 1 and maintains 204 mAh g- 1 at 400 mA g- 1.This "temperature-gradient carbonization combined with NH4Cl activation" strategy balances high capacity and fast charge-discharge kinetics in biomassderived carbon through synergistic tuning of interlayer spacing (0.392 nm) and mesoporous structure (3.296 nm). The work offers a low-cost, eco-friendly route to convert waste biomass into practical sodium-ion battery anodes.

The loading of cocatalysts is a necessary means to improve the photocatalytic performance of alpha-Fe2O3. However, the direct effect of charge transfer between alpha-Fe2O3 and cocatalysts on the efficiency of photoelectrochemical water oxidation. Here, we synthesized CoCu-MIm/TMA/Ti-Fe2O3 composite photoanode using Cu2+-regulated imidazole based cobalt (Co) complex (CoCu-MIm) as a cocatalyst based on energy level matching, and introduced trimellitic acid (TMA) as a bridging agent between Ti-Fe2O3 and cocatalyst CoCu-MIm through coordination assisted synthesis. The research results indicate that trimellitic acid not only acts as a molecular passivator to reduce the number of recombination centers and charge transfer resistance, but also as a bridge to promote charge transfer between Ti-Fe2O3 and CoCu-MIm under the drive of the interfacial electric field (IEF). Meanwhile, the bridging coordination of trimellitic acid also enhances the stability of CoCu-MIm chelation on Ti-Fe2O3. The photocurrent density of the final CoCu-MIm/TMA/Ti-Fe2O3 photoanode reached 4.45 mA/cm(2) at 1.23 V vs. RHE, which is 10 times that of Ti-Fe2O3. This work emphasizes the significance of coordination bridging between cocatalysts and photoanodes for interfacial charge transfer, providing a new option for improving the efficiency of charge transfer at the photoanode solid-solid interface.

Photocatalysis-coupled advanced oxidation rapidly mineralizes pollutants; here we engineer a Fe-CoS2/ZnIn2S4 composite catalyst that activates peroxymonosulfate under visible light to eliminate tetracycline within minutes. The structure, morphology, composition, and optical properties of the photocatalyst were analyzed in detail. FeCoS2/ZnIn2S4 exhibited markedly improved degradation performance, achieving 88 % TCH removal within 10 min and 94.6 % degradation efficiency within 30 min. The separation and transfer characteristics of photogenerated charges were investigated via surface photovoltage (SPV), transient photovoltage (TPV), photoluminescence (PL) spectroscopy, and UV-visible diffuse reflectance spectroscopy (UV-Vis DRS). Furthermore, the degradation of organic pollutants by sulfate radical-based advanced oxidation processes (SR-AOPs) assisted by photocatalysis was thoroughly studied. The test results demonstrate that the synergistic effects of metal nanoparticle loading and heterojunction construction enable the composite catalyst to achieve efficient photogenerated-carrier separation and rapid Co3+ /Co2+ cycling, thereby accelerating PMS activation and generating abundant radicals for pollutant removal. This study offers new insights for developing highly efficient PMS photo-activators for water treatment.

Loading cocatalysts is a necessary means to improve the performance of alpha-Fe2O3 photoanode, and the charge transfer characteristics at the interface between the two directly affect the efficiency of photoelectrochemical water splitting. In this work, we designed and constructed a high-performance ZnCoMn-LDH/B/Ti-Fe2O3 photoanode using a combination of borate post-treatment and electrochemical deposition methods. The results showed that the composite photoanode achieved a photocurrent density of 4.05 mA/cm2 at 1.23 V vs. RHE, 7 times that of Ti-Fe2O3. In-depth studies revealed that the high activity of the ZnCoMn-LDH/B/Ti-Fe2O3 photo-anode is partly due to the ZnCoMn-LDH itself exhibits good electrocatalytic activity, and its nanosheet structure increases the electrochemical active surface area. On the other hand, work function measurements demonstrated that Zn2+ acts as a p-type dopant that can lower the Fermi level of CoMn-LDH, promoting the formation of a stronger built-in electric field at the interface between ZnCoMn-LDH and Ti-Fe2O3. Meanwhile, post-treatment with borate solution passivates the acceptor surface states on Ti-Fe2O3, significantly reducing the transmission resistance of photogenerated holes across the solid-solid interface.

ABSTRACT The simultaneous accumulation of photo‐holes and the specific activation of substrates present a significant challenge in photo‐oxidation. Herein, we propose a dual‐channel collaborative catalytic platform based on hollow TiO2 microspheres, using Cu single‐atom (SA) catalysts and a composite polymer chain, to create separating pathways for unidirectional photogenerated electron/hole extraction. Ferrocene‐functionalized graphene quantum dots are incorporated within the polymer chain for driving benzylamine (BA) oxidation. Quasi in situ transient photovoltage and femtosecond transient absorption tests reveal that leveraging the ultrafast charge separation capability of Cu SAs (0.44 ps) not only accelerates hole transport kinetics but also induces requisite Lewis acidity for the adsorption and activation of BA. In an air atmosphere, the rate of imine production reaches 4.81 mmol g−1 h−1 (selectivity of 98%). This study demonstrates the rational design of an SA/polymer chain dual‐driven catalytic platform for optimizing kinetics and precisely controlling photocatalytic transformations in organic chemistry.

Solar energy is widely recognized as a sustainable and environmentally benign power source, garnering significant interest from the research community. Currently, major efforts are being directed towards the development of integrated technologies that use photoactive nanocomposites. This innovative approach aims to efficiently harness solar energy while effectively mitigating its inherent intermittence through energy storage solutions. In this framework, the photoactive nanocomposite consists of a MoO3 coating on TiO2, sensitized by dye molecules. Upon illumination, the photoexcited electrons generated by the dye* are transferred through TiO2 to the MoO3/electrolyte interface and stored through Li+ intercalation. The incorporation of TiO2 as an electron transport layer mitigates the recombination of photoinduced charge carriers at the interface, extends their lifetime, and further improves both the conversion efficiency and discharge capacity of the solar energy. The TiO2/MoO3/N3//I-/I3-/Pt solar rechargeable device attains a discharge capacity of 0.0103 mA h cm-2 in as fast as 5 min and achieves a conversion efficiency of 1.80% under 1 sun illumination.

Efficient photocatalysts are key to achieving efficient photoactivation of AOPs based on PMS. In this work, a sulfur-rich vacancy magnetically separable Fe-0/CoS2-S-v photocatalyst with high surface adsorption capacity and rapid PMS activation capacity was designed for the efficient degradation of typical antibiotics. A tetracycline removal rate of 92.2 % and a high TOC mineralization rate were achieved within 4 min in the PMS/Vis system. The excellent catalytic performance was attributed to the synergistic effect of Fe, Co, and S on PMS activation and the generation of sulfur-oxygen vacancies by the composites. These vacancies greatly enhanced the catalytic performance of the PMS system, where the generated singlet oxygen (O-1(2)) was identified as the main active substance in the degradation process. In addition, the SO42- based photocatalytic-assisted advanced oxidation processes (SR-AOPs) for the degradation of organic pollutants were thoroughly investigated. XPS comparisons before and after the catalyst reaction revealed that the reducing nano-Fe-0 and metastable S-2(2-) promoted the cycling between Co3+ and Co2+, thus accelerating the rapid activation of PMS. This work provides a new perspective for the further development of efficient and rapid PMS photo-activators for environmental remediation in water bodies.

Photocatalytic synthesis of H 2 O 2 is a proton-coupled electron transfer (PCET) process, which is generally jeopardized by the kinetic mismatch between photogenerated electron transfer and proton supply. To address the challenge, here we proposed a new core–shell design of nanocomposite catalysts comprising of carbon quantum dot (CD)-topped TiO 2 nanoparticles encapsulated by polydopamine (PDA) shells, which delivered stable catalytic activity across a pH range of 1–9, exhibiting a photocatalytic generation rate of H 2 O 2 that reached 18.14 mmol g −1  h −1 in methanol and 8.66 mmol g −1  h −1 in water. This extraordinary, pH-tolerant photocatalytic generation of H 2 O 2 was benefited from the innovative use of CDs, interspaced between the TiO 2 cores and PDA shells, not only as a reservoir of protons to buffer the local acidic microenvironment but also as a proton/electron dual booster to sustain an excellent kinetic match between the proton and photogenerated electron transfer, thus enabling the O 2 reduction to selectively proceed via two-electron reaction pathway over a wide pH span.

To improve the oxygen evolution reaction (OER) performance of zinc-air batteries (ZABs), semiconductor materials are used as the air cathode to introduce photogenerated charge carriers, thereby enhancing the charging performance of the batteries. In this study, CoMn2O4 was loaded onto Ti-Fe2O3 through hydrothermal treatment followed by calcination, successfully constructing the CoMn2O4/Ti-Fe2O3 composite electrode, which was used as the air cathode of a photo-assisted ZAB. The composite electrode exhibited outstanding performance, with the OER onset potential as low as 0.80 V (vs. RHE) and the oxygen reduction reaction (ORR) onset potential of 0.68 V (vs. RHE). Under light irradiation, the battery demonstrated excellent charge-discharge performance at a current density of 0.1 mA cm-2, with a charging voltage of 1.22 V, a discharging voltage of 0.97 V, and a round-trip charge-discharge efficiency as high as 79.5 %.

The effect of calcination temperature (600–850 °C) on the structure and electrical properties of Na0.52Bi0.48TiO3-δ (NBT) synthesized via solid-state reaction has been systematically investigated. The structure, morphology, and electrical properties of the samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS), respectively. Perovskite phase formation initiates above 700 °C, with complete transformation occurring at higher temperatures. SEM analysis demonstrates grain size reduction and impurity emergence at temperatures exceeding 700 °C. Grain boundary conductivity (σgb) exhibits a non-monotonic dependence on calcination temperature: peak conductivity (2.1 × 10−3 S/cm at 500 °C) was achieved at 650 °C, and minimum conductivity was observed at 850 °C. Activation energy dominates conductivity behavior rather than oxygen vacancy concentration. Maximum grain boundary conductivity occurs at 600 °C. Impurity coverage ratio emerges as the primary factor governing grain boundary conduction. Our work establishes calcination temperature as a critical process parameter for NBT-based materials, providing fundamental insights into conduction mechanisms in bismuth titanate systems. And it offers practical guidelines for optimizing solid-state synthesis of oxygen ion conductors. These findings advance the understanding of structure–property relationships in NBT materials and demonstrate the importance of thermal processing control for developing high-performance electrolytes in solid oxide fuel cells and related electrochemical devices. The work particularly highlights the competitive conductivity achievable through optimized calcination conditions without requiring compositional modification.

Photocatalytic coupled SO4 center dot- based advanced oxidation processes (SR-AOPs) are considered as an advanced wastewater treatment technology for degrading pollutants. In this work, Co-doped g-C3N4 (CCN) photocatalysts were successfully designed for activation of permonosulfate (PMS) under visible light to efficiently degrade tetracycline (TC). The CCN photocatalyst exhibited enhanced degradation efficiency, removing 95.9 % of TC within 20 min, with a much higher degradation rate constant (0.1354 min-1) than that of the photocatalytic system (0.0090 min-1) and the SR-AOPs system (0.0538 min-1). The separation and transport properties of photogenerated carriers were probed with the assistance of measurements including surface photovoltage and photoluminescence. The results showed that the introduction of Co promoted the effective separation of photogenerated charges in CCN, which accelerated the Co3+/2+ cycle and realized the efficient activation of PMS. Overall, this study provides a new strategy for the development of efficient photocatalytic activation of PMS for rapid degradation of organic pollutants.

alpha-Fe2O3 is a promising photoanode material, but its photoelectrochemical (PEC) properties are severely limited by harmful surface states and unclear interfacial structure-activity relationships with cocatalysts. In this work, we innovatively introduces gallic acid (GA) as a coordinating agent and successfully encapsulates the tannin Co (TACo) complex onto Ti-Fe2O3 in a conformal manner. Specifically, through surface photovoltage systems, transient absorption spectroscopy (TAS) analysis, and self-designed transient photocurrent in-situ testing (TPC), we have confirmed that gallic acid not only acts as a bridge between Ti-Fe2O3 and TACo, but also actively regulates the surface state of Ti-Fe2O3. In addition, the coordination effect of GA constructs an efficient charge transfer channel, significantly promoting the water oxidation reaction process involving holes. The photocurrent density of the synthesized Ti-Fe2O3/GA/TACo reached 3.3 mA/cm2 at 1.23 V vs. RHE, which is 1.68 and 10 times higher than Ti-Fe2O3/TACo and Ti-Fe2O3, respectively. The bridging effect of small molecules in this study provides a clear interface for the study of charge transfer and structure-activity relationships.

The extensive solid-liquid interface between the photoanode and the electrolyte solution impedes the kinetics of the oxygen evolution reaction (OER), resulting in a photoelectrochemical (PEC) water splitting efficiency that falls short of theoretical predictions. In this study, by depositing a metal-phytate complex (CoCu-PA) coating onto Ti, Zr co-doped Fe2O3 via a hydrothermal method, we successfully fabricated a CoCu-PA/Ti,Zr:Fe2O3 composite photoanode for water oxidation. Various characterization techniques and electrochemical analyses indicated that Ti, Zr co-doping enhanced the conductivity of Fe2O3. More importantly, owing to the highly hydrophilic property of CoCu-PA, the charge transfer resistance at the interface between the composite photoanode and the solution is significantly reduced. Furthermore, a built-in electric field was formed within the photoanode, facilitating the rapid migration of photogenerated charges and their efficient injection into the electrolyte to participate in the OER. As a result, the CoCu-PA coating enhanced the OER kinetics of the composite photoanode and led to a photocurrent density of 3.4 mA/cm2. This study offers new insights into the design of composite photoanodes to improve charge migration efficiency both within the bulk material and at the solid-liquid interface.

Building upon the Na0.5Bi0.49-xCaxTi0.99Mg0.01O3-δ system previously reported for its optimal electrical performance, we synthesized a series of calcium-doped ceramics with compositions Na0.5Bi0.49-xCax- Ti0.99Mg0.01O3-δ (x = 0, 0.01, 0.02, 0.03) using the solid-phase method. The ceramics underwent precisely controlled two-step thermal processing: initial calcination at 800 °C followed by sintering at 1000 °C, with rigorous stoichiometric control maintained across all samples. The samples were characterized by XRD, SEM, and AC impedance spectroscopy to study the effect of Ca2+ doping concentration on the crystal structure, morphology and electrical properties of samples, specially, the bulk conductivity ( σ_b ), grain boundaries conductivity ( σ gb ), and total conductivity ( σ_t ), which obtained by the fitted impedance spectra, were analyzed in detail to reveal the effect of Ca2+-doping on the electrical performance. The findings revealed that all the samples displayed a pure perovskite phase without discernible impurity peaks. Furthermore, the average grain size of the samples decreased as the doping concentration was increased, suggesting that Ca2+ play a role in retarding grain growth. Upon substitution of Bi3+ with Ca2+, the grain conductivity peaked at a doping ratio of x = 0.02. The grain boundary conductivity, on the other hand, increased initially with the rise in x before declining, reaching its maximum at x = 0.01. Consequently, the total conductivity was found to be at its highest when x = 0.01.

Sc ^3+ was chosen as the dopant, and two series of samples, Na _0.5 Bi _0.49-x Sc _x TiO _3- _δ (abbreviated as x Sc-Bi, x = 0–0.05) and Na _0.5 Bi _0.49 Ti _1-x Sc _x O _3- _δ (abbreviated as x Sc-Ti, x = 0–0.07), were synthesized via the solid-state method. The influence of Sc ^3+ doping at distinct lattice sites on the structural, microstructural, and electrical properties of Na _0.5 Bi _0.49 TiO _3- _δ oxygen-ion conductors was systematically investigated. The results reveal that at low doping concentrations (x ≤ 0.02), Sc ^3+ tends to occupy the Bi ^3+ sites, while at higher concentrations (x > 0.02), it favors the Ti ^4+ sites. Sc ^3+ occupies the Bi ^3+ sites and inhibits grain growth, while it occupies the Ti ^4+ sites and facilitates grain growth. In terms of grain conductivity, the x Sc-Bi series samples exhibit superior performance. In terms of grain boundary conductivity, Sc ^3+ doping significantly reduces grain boundary resistance. At low doping concentrations, the x Sc-Bi series exhibits higher grain boundary conductivity than the x Sc-Ti series; however, at higher concentrations, the x Sc-Ti series outperforms the x Sc-Bi series. Given that grain boundary resistance dominates the total resistance, the x Sc-Ti series samples also exhibit higher total conductivity.

To improve the oxygen evolution reaction (OER) kinetic performance of zinc-air batteries, the photoassisted strategy was utilized to introduce photogenerated carriers, enhancing the OER catalytic performance and thus improving the battery charging efficiency. Accordingly, in this work, commercial sulfonated cobalt(II) phthalocyanine (CoPcS) was loaded onto the surface of Ti-Fe2O3 electrodes via a hydrothermal method. Subsequently, the CoPcS/Ti-Fe2O3 composite electrode was successfully fabricated and applied in photoassisted zinc-air batteries (ZABs). The composite electrode demonstrated excellent performance: the OER onset potential was as low as 0.75 V (vs RHE), and the ORR limiting current density reached 1.28 mA cm-2 under the condition of 0 V (vs RHE). At a current density of 0.1 mA cm-2 under illumination, the battery had excellent charge-discharge performance, with the charging voltage being 1.187 V, the discharging voltage being 1.108 V, and the charge-discharge round trip efficiency being as high as 93.3%.

alpha-Fe2O3 is a promising photoanode that is limited by its high surface charge recombination and slow water oxidation kinetics. In this study, we synthesized a TiO2 layer on Ti-Fe2O3 by annealing Ti-MOFs, followed by ZIF-67 as a co-catalyst, to fabricate a ZIF-67/TiO2/Ti-Fe2O3 photoanode for photoelectrochemical (PEC) water splitting. The systematic experimental and theoretical results revealed that the improvement in performance was due to multiple effects of the MOF-derived TiO2. This molecule not only passivates the acceptor surface states of Ti-Fe2O3, thereby reducing the number of surface recombination centers, but also acts as an electron barrier to promote charge separation in the Ti-Fe2O3 bulk. Moreover, MOF-derived TiO2 can dramatically reduce the energy barrier for the OER of Ti-Fe2O3, thus promoting the conversion of the intermediate *OH into *O. The synergistic improvement in the bulk and surface properties effectively enhanced the water oxidation performance of Ti-Fe2O3. The ZIF-67/TiO2/Ti-Fe2O3 photoanode exhibits a photocurrent density of up to 4.04 mA cm-2 at 1.23 V vs. RHE, which is 9.4 times as that of pure Ti-Fe2O3, and has long-term stability. Our work provides a feasible strategy for constructing efficient organic-inorganic hybrid photoelectrodes. Published by Elsevier B.V. All rights reserved.

Mass transfer enhancement and crystallinity engineering are two prevailing technologies for photocatalyst modification. However, their relative effectiveness in enhancing photocatalytic activity remains unclear due to the lack of rational probing catalysts. In this study, we synthesized two distinct carbon nitride (C3N4) catalysts: one with a high specific surface area (CN-HA) and the other with improved crystallinity (CN-HC). These catalysts served as probes to compare their respective impacts on photocatalytic activities. Comprehensive characterization techniques and density functional theory (DFT) calculation results unveiled that crystallinity played a dominant role in light absorption and charge dynamics, while surface area primarily influenced mass transfer in photocatalysis. Importantly, our findings revealed that crystallinity engineering of photocatalyst achieved a greater impact on photocatalytic hydrogen evolution than that from mass transfer enhancement. Consequently, CN-HC demonstrated a remarkable improvement in photocatalytic performance for hydrogen evolution (6465.4 mu mol h-1 g-1), surpassing both C3N4 and CN-HA by 19.4- and 2.4-fold, respectively, accompanied by a high apparent quantum yield of 23.8 % at 420 nm. This study not only unveils the dominant factor influencing the activity of photocatalysts but also provides a modified approach for robust solar fuel production, shedding light on the path toward efficient and sustainable energy conversion.