Conjugated polymers demonstrate potential for photocatalytic hydrogen peroxide (H2O2) generation; however, their inadequate aqueous dispersibility leads to interfacial mismatch and inconsistent hydrophilicity, thereby hindering the migration of charge carriers and ionic species at the water-photocatalyst interface. In this work, three conjugated polymers TAQ, TPPQ, and TMPQ, exhibiting aggregation-enhanced H2O2 production are designed and synthesized. Subsequently, their quasi-homogeneous photocatalytic systems are fabricated in aqueous media via the nanoprecipitation method assisted by an amphiphilic surfactant, facilitating effective H2O2 generation. Under an atmosphere devoid of sacrificial agents, the quasi-homogeneous systems of TAQ, TPPQ, and TMPQ exhibit H2O2 production rates 27-58 times higher than their powder forms. Notably, TAQ achieves a H2O2 production rate of 3915µmol g-1 h-1 and an apparent quantum yield of 24.6% at 400 nm, representing some of the highest values reported for single-junction polymer-based photocatalysts. These findings underscore the efficacy of quasi-homogeneous system design in markedly improving photocatalytic performance.

Enhancing the spectral response range of photocatalysts is an effective method to improve photocatalytic efficiency. For wide-bandgap photocatalysts, defect engineering can narrow the bandgap and improve visible-light utilization. However, the resulting band-edge positions may still be unsuitable for photochemical redox reactions, leading to thermodynamic constraints on activity. Recent studies have shown that the localized surface plasmon resonance (LSPR) effect, which arises from the interaction between metal nanoparticles and light, can generate a significant number of "hot electrons" by responding to visible and near-infrared light. These hot electrons, when injected into the photocatalyst, significantly enhance the photocatalytic efficiency. Moreover, this effect, due to its unique structure, can also increase the oxidation-reduction reaction rate, electron transport efficiency, and polarization degree of molecules adsorbed on the photocatalyst surface. As a result, LSPR has become one of hot spots in the design and research of efficient photocatalysts. Therefore, this paper reviews carefully LSPR effect in depth from its physical mechanism to photocatalytic application. The article describes the basic concepts of the LSPR effect and its influencing factors, including the size and shape of the nanoparticles, the dielectric constant of the surrounding environment, and the interband jump of the metal itself. Subsequently, we summarize LSPR-enabled photocatalysis in representative reactions, including water splitting, CO2 reduction, and pollutant degradation. Finally, we discuss the remaining challenges and future opportunities of LSPR-enhanced photocatalytic systems, and propose strategies to further optimize LSPR-driven performance for energy conversion and environmental remediation.

Light-driven biohybrid systems for nitrogen removal: Insights into intimate coupling of photocatalysis with biodegradation systems and photocatalytic biohybrid systems.

Solar energy-driven hydrogen peroxide (H2O2) synthesis from atmospheric oxygen and water represents a sustainable and highly promising avenue for the production of this essential chemical. Covalent organic frameworks (COFs) offer a molecular platform for the direct conversion of solar energy to H2O2, however, they are persistently plagued by the recombination of photogenerated charge carriers, a phenomenon induced by σ-bond rotation under light irradiation, which typically leads to sluggish conversion kinetics and suboptimal efficiency. We herein present a molecular engineering strategy involving the construction of noncovalent trans rings (Nc-TRs) within COFs. This approach entails the precise introduction of noncovalent interactions between donor and acceptor moieties, thereby constraining the free rotation of σ bonds and substantially suppressing the recombination of photogenerated charge carriers. Experimental and theoretical investigations demonstrate that the incorporation of Nc-TR within TAPT-DHBD COFs reduces the molecular dihedral angle from 37.33° to 0°, thereby optimizing molecular coplanarity and prolonging the photogenerated charge carrier lifetime by 820% compared to TAPT-TPD COFs devoid of Nc-TRs. Our findings further reveal that TAPT-DHBD COFs exhibit 5.0-fold and 3.6-fold enhancements in H2O2 photocatalytic conversion kinetics and solar-to-chemical conversion (SCC) efficiency, respectively, relative to TAPT-TPD COFs. We further demonstrate that H2O2 solutions generated in the flow-type photocatalytic system under solar irradiation exhibit a record-high antibacterial efficacy of 107 cfu s-1, and achieve a 100% wound healing rate within 7 d, markedly outperforming commercial physiological saline.

Organic semiconductors offer a uniquely versatile and cost-effective platform for solar-driven hydrogen generation from water by leveraging scalable and earth-abundant material design. Their high degree of tunability in molecular, optical, and electronic structures has enabled drastic improvements in solar absorptivity, energy level alignment with redox potentials of hydrogen evolution, longer photogenerated charge carrier lifetimes, and improved overall kinetics. This review focuses on the photocatalytic hydrogen generation from water, highlighting the key challenges that continue to limit performance and practical implementation. In particular, we examine recent strategies to address insufficient light absorption, inefficient charge carrier separation, and poor long-term stability across a broad range of organic semiconductor platforms, including conjugated polymers, covalent organic frameworks, and supramolecular assemblies. Finally, we provide an outlook on underexplored opportunities in both reaction kinetics and material design, providing approaches to overcome these persistent limitations and advance organic-semiconductor-based photocatalytic systems.

This research is dedicated to improving the efficacy and durability of graphdiyne (GDY), a novel 2D carbon allotrope, for applications in photocatalytic hydrogen generation. Addressing issues such as the relatively poor stability of GDY in practical applications, we innovatively employed a high-entropy oxide (HEO) to replace conventional copper substrates, successfully preparing an HEO-GDY composite. This was further integrated with Zn0.5Cd0.5S to construct the ZHG-10 photocatalyst. Experimental results demonstrate that ZHG-10 exhibits superior photocatalytic hydrogen evolution activity and cycling stability in comparison to GDY-based catalysts synthesized from Cu or Cu2+ precursors, achieving a hydrogen production rate of up to 7.59mmol/g/h. Photoelectrochemical tests reveal that the multi-element chemical environment of HEO significantly enhances the separation efficiency of photogenerated charge carriers. Kelvin probe force microscopy (KPFM) analysis and density functional theory (DFT) calculations indicate that the multi-metal synergy and lattice distortion effects in HEO introduce numerous defective active sites (e.g., oxygen vacancies), which not only serve as efficient centers for hydrogen adsorption and activation but also significantly optimize interfacial charge transfer pathways. This study elucidates the dual functionality of HEO-GDY in enhancing charge carrier separation and providing abundant active sites, offering a new strategy for developing high-performance and durable GDY-based photocatalytic systems.

Polymeric carbon nitride (C3N4) has emerged as a promising photocatalytic material, yet its photoconversion efficiency remains constrained by strongly bound excitons that impede free carrier generation. While structural or electronic modifications can lower the exciton binding energy, the detrimental role of exciton-phonon coupling in nonradiative decay is often overlooked. Here, we present an isotopic strategy by integrating hydrothermally synthesized deuterated carbon dots (d-CD) into C3N4 to construct d-CD/C3N4 composites, with negligible alteration to the bandgap. Temperature-dependent photoluminescence spectroscopy reveals that deuteration not only reduces the exciton binding energy from 72.8 to 60.9 meV, but also weakens the exciton-phonon coupling strength from 977 to 794 meV. This suppression of exciton-phonon coupling mitigates nonradiative recombination, prolonging the charge carrier lifetime from 0.117 to 0.570ms, as confirmed by transient photovoltage measurements. The stabilized long-lived carriers further facilitate electron extraction, evidenced by enhanced electron transfer to methyl viologen as an effective electron mediator. As a result, d-CD/C3N4 exhibits a 1.7-fold improvement in photocatalytic hydrogen evolution relative to its non-deuterated counterpart. These findings underscore isotope engineering as an effective approach to regulate exciton-phonon interactions and charge carrier dynamics across the ps-ms timescale, offering a new dimension for tuning the optoelectronic behavior of C3N4-based photocatalytic systems.

Multipath radical synergistic activation of hydrogen peroxide by colloidal-clay composite gel microspheres: Reaction mechanism and efficient photocatalytic degradation of p-Nitrophenol.

Atomic layer deposition of ZnO on NH2-MIL-125(Ti) for enhanced selective CO2 to CH4 conversion via S-scheme heterojunction engineering.

Hydrogen-bonded water clusters (H2O)n obscure the intrinsic reactivity of monomeric H2O (n = 1) by restricting molecular reorientation. Elucidating the catalytic behavior of isolated water remains a key challenge in aqueous-phase chemistry. Here, we address this by designing a molecular crystal that uniformly confines single water molecules in identical tetrahedral cavities. This platform, CB-H2O, exhibits exceptional activity for photocatalytic H2O-to-H2O2 conversion, achieving 7.03mmol g- 1 h- 1 with pure water, representing an 11.6-fold enhancement over cavity-deficient controls and being markedly superior to existing photocatalytic systems. This performance advantage is directly attributed to the crystallographically defined monomeric water, as verified by isotopic labelling and in-situ spectroscopy. Theoretical calculations further demonstrate that cavity confinement eliminates hydrogen-bond reorganization penalties, substantially lowering the activation barrier for water oxidation. Our work establishes monomeric-water catalysis as a distinct and efficient paradigm, showcasing molecular crystal engineering as a versatile approach to tailoring water-involved reactions for sustainable catalysis.

Water promoted lignin C–C bond cleavage in Bi4O5Br2@BiOBr heterojunction photocatalytic system

Efficient photocatalytic conversion of biomass-derived hydroxyl acids to amino acids over Ni/CdS.

Schottky junction- and oxygen vacancy-driven charge separation for enhanced photocatalytic degradation of toluene over sodium- and palladium-modified titanium dioxide.

Light-triggered controllable carbon monoxide (CO) release represents a promising approach for cancer therapy but is limited by the poor tissue penetration of light and insufficient CO release rates within deep tumor microenvironments. Herein, inspired by near-infrared (NIR)-activated multiphoton photocatalysis, a novel zinc-based metal-organic framework (ZnTBH) is reported, for the first time, to enable effective NIR-mediated synergistic therapy through combined CO gas therapy and photodynamic therapy (PDT) in deep-seated tumors. The engineered MOF integrates a V-shaped Tröger's base (TB) derivative with an A-π-A configuration as the organic linker, synergistically enhancing CO2 adsorption to overcome the "dilute CO2" challenge in tumors while enabling efficient endogenous CO2-to-CO conversion via NIR-driven multiphoton photocatalysis. Moreover, the photogenerated holes localize on biphenyl-4,4'-dicarboxylic acid can drive water oxidation to hydroxyl radicals (•OH), thereby further improving therapeutic efficacy. This study presents a significant advancement in the design of NIR light-driven photocatalytic systems for safe, precise, and localized CO delivery, offering new opportunities for CO-based or combination therapies in the treatment of deep-seated tumors.

The purpose of the study was to investigate novel and green-synthesized ZnO NPs derived from C. cyminum seeds for photocatalytic degradation of the Direct Yellow 86 dye under UV irradiation. The green catalyst cumin-derived Zinc Oxide NPs (GC-C-ZnO NPs) were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), and X-Ray Diffraction (XRD). A Box-Behnken Design (BBD) determines optimal conditions for DY86 removal, achieving 94% efficiency at pH 11.0, dye concentration of 30 mg L-1, catalyst dose of 0.12 g L-1, and a time of 30 min. The predictive model was statistically validated by analysis of variance (ANOVA), confirming a high correlation coefficient (R2 0.99). Significance was also verified by :{R}_{adj}^{2} 0.99 and :{R}_{prd}^{2} 0.98 values. The model and all parameters exhibited exceptional statistical significance (F-value 281.00, P-value < 0.0001). Liquid chromatography-mass spectrometry (LC-MS) analysis confirms diminished peaks at m/z 318.70 after photocatalysis by the GC-C-ZnO NPs. This investigation successfully advanced an efficient, eco-friendly photocatalytic system for enhanced water and wastewater purification. The study demonstrates that GC-C-ZnO NPs provide an efficient and eco-friendly photocatalytic system for the removal of organic dyes from textile wastewater.

Abstract In this work, an efficient hybrid photocatalyst was developed for solar-driven hydrogen production, a promising pathway for sustainable energy generation. A new photoelectrochemical water-splitting catalyst was designed and synthesized from graphene oxide, cyclotriphosphazene, BODIPY, and B, F co-doped TiO 2 as core structural components. The catalytic performance of the composite was evaluated in photoelectrochemical water reduction. The structures and morphologies of the synthesized materials were characterized by spectroscopic methods. In addition, photophysical properties were examined using diffuse reflectance, UV–visible, and fluorescence spectroscopy, while electrochemical behavior was investigated with photocurrent, electron impedance spectroscopy, and Mott–Schottky measurements. The composite powders were coated onto conductive FTO glass by electrophoretic deposition, and their hydrogen production efficiency was measured in a photoelectrochemical setup. The B, F co-doped TiO 2 /graphene oxide hybrid functionalized with BODIPY-substituted cyclotriphosphazene exhibited significantly enhanced photocatalytic performance (409.2 µmol h⁻ 1 cm⁻ 2 ), surpassing bare and doped TiO 2 , graphene oxide, and comparable systems reported in the literature. This study not only demonstrates the synergistic role of molecular engineering and heteroatom doping in photocatalytic systems but also charts a forward-looking path toward next-generation, high-efficiency solar-to-hydrogen conversion materials.

Beyond powder-suspension photocatalytic systems, monolithic photocatalysts featuring excellent recyclability and enhanced light utilization efficiency have been promising candidates for large-scale solar-driven photocatalytic water splitting, yet often suffer from complex fabrication processes and reliance on the use of expensive scaffolds and additional cocatalyst loading. Herein, we develop monolithic photocatalysts via utilizing a cocatalyst sheet (Fe2P/RB) derived from red brick (RB) by vapor-phase phosphidation as a scaffold to anchor particulate semiconductors (e.g., CdS, Zn0.5Cd0.5S, TiO2, and g-C3N4), for solar-driven photocatalytic H2 production from the water splitting. The endogenous Fe oxides within RB sheet are in situ converted into embedded Fe2P during phosphidation, serving as electron sinks to promote charge separation and H2-evolving active sites to improve water splitting performance. Impressively, the monolithic CdS-Fe2P/RB photocatalyst sheet achieves a visible-light (λ ≥ 420nm) photocatalytic HER rate of 7.7mmol gCdS -1 h-1 and an apparent quantum yield (AQY) as high as 30.5% at 420nm, which are 12.4 and 3.2 times higher than that of the powder-suspension system, respectively. Furthermore, the excellent integrity enables CdS-Fe2P/RB to stably produce H2 for 120h with negligible activity decay. This work offers an effective strategy for the rational designs of cost-efficient and high-performance monolithic photocatalysts for solar water splitting.

Solar-driven photocatalytic seawater splitting for hydrogen production represents a crucial green technology pathway for achieving a sustainable energy supply. In this study, a series of tremella-like porous graphitic carbon nitride photocatalysts (CNC-x) were constructed via a supramolecular self-assembly strategy to enhance the photocatalytic hydrogen evolution from seawater. The optimized CNC-1.4 achieved a hydrogen evolution rate of 4.7 mmol·g-1·h-1 in natural seawater containing triethanolamine (TEOA) under visible-light irradiation, which is nearly 20 times higher than that of bulk g-C3N4 (0.23 mmol·g-1·h-1). Moreover, under natural sunlight (10:00-16:00), CNC-1.4 maintained a hydrogen evolution rate of approximately 4.9 mmol·g-1·h-1 and exhibited excellent cycling stability. These results demonstrate good seawater tolerance during sacrificial-agent-assisted hydrogen evolution and highlight the promising potential for practical solar-driven hydrogen production in seawater. Finally, by systematically comparing the photocatalytic performance in pure water, artificial seawater, and natural seawater under sacrificial-agent-free conditions, we further confirmed that only in the presence of TEOA can the system achieve efficient hydrogen evolution in seawater while effectively suppressing the associated side reactions. This study provides a new design strategy for constructing efficient g-C3N4 based photocatalytic systems and lays an essential foundation for practical solar-powered direct hydrogen production from seawater.

To investigate the treatment performance of a CuTiO3 photocatalytic system for organic peroxide production wastewater under visible light, CuTiO3 powder prepared through the hydrothermal method was used for this experiment. The light absorption properties of the CuTiO3 catalyst were analyzed using UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS). The effects of the initial pH, photocatalyst dosage, light intensity, and reaction duration on the photocatalytic reaction were examined. Before and after the reaction, the changes in pollutant components in water were characterized via three-dimensional excitation–emission matrix fluorescence spectrometry (3D-EEM) and gas chromatography–mass spectrometry (GC-MS); the changes in the concentrations of some pollutants were analyzed via wavelength scanning. The results indicated that CuTiO3 has a good response to visible light. Under the optimized conditions (initial pH = 5, CuTiO3 dosage = 1.2 g/L, light intensity = 1300 W/m2, duration = 4 h), the COD removal rate reached 58%, and the B/C (BOD5/COD) ratio of wastewater increased from 0.112 to 0.221, demonstrating a good pretreatment effect. GC-MS analysis demonstrated significant degradation effects on amide and hydride substances. Radical capture experiments verified hydroxyl radicals as the dominant species in CuTiO3 photocatalysis. Visible-light photocatalysis using CuTiO3 provides an efficient pretreatment pathway for organic peroxide production wastewater.

The intensifying climate emergency compels a rapid paradigm shift from fossil fuel-based energy systems toward sustainable, carbon-neutral alternatives. Among emerging strategies, the photocatalytic valorization of CO2 into energy-dense fuels and commodity chemicals by suitable photocatalysts presents a straightforward and economically viable solution for both greenhouse gas mitigation and renewable energy storage. In this context, covalent organic frameworks (COFs) have emerged as a highly promising class of crystalline, porous semiconductor photocatalysts for CO2 reduction reactions (CO2RR), owing to their structural regularity, modularity, and optoelectronic tunability. In this review, we comprehensively outline the recent progress in three distinct categories of COF-based photocatalytic systems: metal-free COFs, single-metal-atom based COFs, and COF-based composites. Key strategies such as the judicious incorporation of donor-acceptor architectures, rational post-synthetic functionalization, and heterojunction engineering are discussed. Insights from in situ operando characterization and theoretical calculations are also presented to highlight the roles of exciton dynamics, charge separation, active site engineering, and structure-function relationship in CO2RR. Finally, we propose future research directions for better utilization of COFs in solar fuel/chemical generation. Overall, this review aims to provide a comprehensive discussion on the advancement of COF-based photocatalysts and next-generation CO2 valorization materials.