The programming and exploitation of molecular materials with the combination of simultaneous dual/multiple chemical and physical performances is a promising strategy but is only in the initial stages of development. In this work, a controllable and feasible method was proposed, involving the integration of isomorphic copper metal-organic frameworks (Cu-MOFs) with different valence states as dual-function materials to fabricate a selective self-powered photocatalytic continuous-flow system, in which the Cu-MOFs were capable of simultaneously regulating the outputs of triboelectric nanogenerators (TENGs) and photocatalytic properties. A flexible and tailorable CuI-MOF could experience a sequential valence state transformation to construct the topologically equivalent isomorphic CuICuII-MOF and CuII-MOF through a solid-gas oxidation process. Owing to the effect of the different valence states in CuI-MOF, CuICuII-MOF and CuII-MOF, the CuI-MOF-TENG and CuII-MOF-TENG exhibited the highest and lowest output performances, respectively. Furthermore, the CuI-MOF-TENG exhibited outstanding durability and stability to directly power blue LEDs, providing blue-light irradiation to conduct self-powered selective photocatalytic continuous-flow coupling reactions with CuI-MOF, CuICuII-MOF and CuII-MOF as photocatalysts. The results showed that CuI-MOF exhibited well-defined platforms with regular and identical CuI active centers to realize an efficient cooperative effect for improving the photocatalytic efficiency. This work presents a candidate approach to fabricate a bifunctional material to achieve the design targets of multitasking in selective self-powered continuous-flow systems.

The unique chemical and physical properties of Ga-based liquid metal (Ga-LM) interfaces present an intriguing platform for the in situ synthesis of novel composites. Mechanical shearing can effectively disperse bulk Ga-LM into micro/nanosized droplets, significantly increasing their interfacial area and enhancing their reactivity. Herein, we report the room-temperature, one-step fabrication of a novel ternary Ga-LM/CuO-NiO heterojunction through the interaction between liquid metal micro/nano droplets and an alkaline solution containing cupric sulfate and nickel nitrate, leading to the simultaneous formation of CuO and NiO. The morphology, elemental composition, chemical states, and crystallographic structure were comprehensively characterized with XPS, SEM, TEM, and XRD. The proposed mechanism for CuO and NiO formation on the LM interface involves the adsorption of [HGaO3]2- species at the interface, which subsequently react with [Cu(NH3)4]2+ and [Ni(NH3)6]2+ complexes concurrently formed in an ammonia solution. This reaction leads to the in situ formation and growth of CuO and NiO nanosheets directly on the LM interface. Band gap analysis shows that the Ga-LM/CuO-NiO composite possesses a narrower band gap (4.74 eV) than the LM (5.64 eV) and LM/CuO (5.48 eV) composites. Finally, the photocatalytic performance was investigated in the degradation of methylene blue, showing an excellent degradation efficiency of 97.1% over the Ga-LM/CuO-NiO composite within 110 min under simulated sunlight. The photodegradation rate constant over the Ga-LM/CuO-NiO composite is 16.5 and 3.4 times higher than those over the LM and LM/CuO composite, respectively. The significant photocatalytic performance of the Ga-LM/CuO-NiO composite is attributed to the synergistic effect of its three components. The brilliant structural stability and reusability of the composite were also confirmed. This study not only introduces a novel synthetic route for Ga-LM-based functional composites but also underscores the immense potential of the reactive Ga-LM interface as a versatile platform for designing advanced materials with enhanced performance, particularly in photocatalytic applications.

Solar-driven interfacial evaporation (SIE) offers a sustainable pathway for water purification, yet it faces a persistent trade-off between high evaporation rate and long-term salt rejection. Here, we design a renewable biomass-derived dual-network hydrogel evaporator based on sodium alginate (SA) extracted from brown algae, integrated with a polypyrrole (PPy) photothermal layer and a polyethylene glycol (PEG) water-state modulator. The SA provides an interconnected macroporous scaffold with abundant –COO− groups, while PEG enhances intermediate water (IW) formation via hydrogen-bond regulation. Under one-sun irradiation, the evaporator achieves a high evaporation rate of ∼4.30 kg m−2 h−1. PEG increases the IW content by 6.8% compared to a PEG-free control, contributing to a 1.46-fold enhancement in evaporation rate. The –COO− groups electrostatically repel Cl− ions and, together with the macroporous architecture (50–200 μm), prevent salt crystallization even in saline water for 7 days. An outdoor demonstration yields a practical water collection of ∼37.09 kg m−2 over 8 h. This work demonstrates that biomass-derived SA can serve as a high-performance, sustainable platform for solar desalination.

Structural instability and sluggish lithium-ion (Li+) kinetics of spinel NiCo2O4 anodes severely hinder their applications in high-energy-density lithium-ion batteries. Mesocrystalline structures exhibit promising potential in balancing structural stability and enhancing reaction kinetics. However, their controlled synthesis mechanisms remain elusive. Herein, a substrate interface engineering strategy is developed to achieve controllable synthesis of mesocrystalline and polycrystalline NiCo2O4 nanorods. Remarkably, mesocrystalline NiCo2O4 exhibits a high capacity retention rate of 85.7% after 500 cycles at 2 A/g, attributed to its porous structure facilitating Li+ transport kinetics and unique stress-buffering effect validated by ex-situ TEM. Theoretical calculations and interfacial chemical analysis reveal that substrate-crystal surface engineering regulates the nucleation-growth pathways: Acid-treated nickel foam enables epitaxial growth via lattice matching, acting as a low-interfacial-energy template to reduce nucleation barriers and promote low-temperature oriented crystallization. In contrast, carbon cloth requires high-temperature thermal activation to overcome surface diffusion barriers induced by elevated interfacial energy. This substrate-driven crystallization kinetic modulation overcomes the limitations of random nucleation in conventional hydrothermal synthesis. The established substrate-crystal interfacial interaction model not only clarifies the kinetic essence of crystal orientation regulation but also provides a universal theoretical framework for lattice-matching design and mesostructural optimization of advanced electrode materials.

Nitric oxide (NO) detection at low concentrations was of significant practical importance for the screening and monitoring of certain respiratory diseases, driving the demand for gas sensors with enhanced performance and reduced power consumption. This study presented a photoinduced NO gas sensor based on layer-like Ni-doped WO3 nanomaterials operating at room temperature (RT). The synergistic effect of Ni doping and photoactivation enabled remarkable gas sensitivity across a low concentration range (10~100 ppb), achieving rapid response/recovery times (28 s/50 s) at 50 ppb under RT. The limit of detection (LOD) for NO molecule could reach below 8.29 ppb. A good linear correlation between the response value and NO concentration was demonstrated under a wide relative humidity range (20~90%). Ni doping induced oxygen vacancies while simultaneously facilitating photoinduced electron transfer for surface oxygen activation. The optimized sensor maintained good response stability after three months of ambient storage, demonstrating excellent operational durability. In situ experimental results further elucidated that the doped Ni site enhanced electron transfer from the surface to adsorbed oxygen molecules, generating superoxide radicals. This work provided fundamental insights into surface engineering strategies for developing optically modulated gas sensors and proposed a viable pathway for constructing energy-efficient exhalation monitoring systems.

S-scheme heterojunction has demonstrated high superiority in the separation and transfer of charge carriers, which is desirable for efficient photocatalytic CO2 reduction into high-value-added chemical feedstocks. Herein, BiOI flake supported on CuBi2O4 rod (CBO/BOI) with oxygen vacancy was in-situ developed. The CBO/BOI composite demonstrates superior photocatalytic performance for CO2 reduction with H2O vapor compared with the individual components. Notably, the product of CO2 reduction changes from CO/CH4 to exclusively CH4 by modulating oxygen vacancies. The CH4 and O2 yields of the optimal CBO/BOI-07 catalyst are 121.7 and 232.6 mu mol/gcat/h under visible light illumination, with an apparent quantum yield of 2.25% at 405 nm. The S-scheme charge transfer mode at the CBO/BOI interface is demonstrated through in-situ XPS analysis and theoretical simulations. Furthermore, the presence of oxygen vacancy significantly influences the adsorptive behavior of *CO intermediates, which is crucial for selective conversion of CO2 to CH4. Based on the in-situ Fourier transform infrared spectroscopy and adsorption studies, the reaction mechanism of photocatalytic CO2 reduction is speculated and experimentally validated.

Hydrogen (H2) monitoring demonstrates significant practical importance for safety assurance in industrial production and daily life, driving the demand for gas-sensing devices with enhanced performance and reduced power consumption. This study developed a room-temperature (RT) hydrogen-sensing platform utilizing two-dimensional (2D) Ag-doped SnS2 nanomaterials activated by light illumination. The Ag-SnS2 nanosheets, synthesized through hydrothermal methods, exhibited exceptional H2 detection capabilities under blue LED light activation. The synergistic interaction between silver dopants and photo-activation enabled remarkable gas sensitivity across a broad concentration range (5.0-2500 ppm), achieving rapid response/recovery times (4 s/18 s) at 2500 ppm under RT. Material characterization revealed that Ag doping induced S vacancies, enhancing oxygen adsorption, while simultaneously facilitating photo-induced hole transfer for surface hydrogen activation. The optimized sensor maintained good response stability after five-week ambient storage, demonstrating excellent operational durability. Experimental results further demonstrated that Ag dopants enhanced hydrogen adsorption-activation, while S vacancies improved the surface oxygen affinity. This work provides fundamental insights into defect engineering strategies for the development of optically modulated gas sensors, proposing a viable pathway for the construction of energy-efficient environmental monitoring systems.

Photocatalytic degradation of antibiotic and organic pollutants in wastewater constituted a pivotal strategy for achieving environmental sustainability. We fabricated a novel S-scheme Mn3O4/BiOI heterojunction, further indepth investigating the photothermal-assisted photocatalytic activity for pollutants degradation. The optimized Mn3O4/BiOI-100 composite exhibited superior full-sunlight- induced catalytic activity for tetracycline degradation, demonstrating more 3.29-fold enhancements compared to pristine Mn3O4 and BiOI. This performance enhancement arose from the effects of efficient charge separation through the S-scheme mechanism and favorable photothermal catalyst surface. Notably, the composite maintained robust catalytic efficiency in complex aqueous matrices containing various ions. Biological validation through rice seed germination assays revealed complete elimination of phytotoxicity in treated pollutant solutions, realizing the value-added catalytic conversion from nocuous molecules. Radical trapping experiments identified center dot OH and center dot O2 - as primary reactive species, consistent with the proposed S-scheme mechanism subsequently verified by in situ XPS analysis. The photocatalytic degradation and COD removal abilities were also significantly enhanced for other six organic pollutants such as rhodamine B, congo red, methyl orange, methylene blue, p-chlorophenol, and phenol. This study provides a design blueprint for constructing photothermal-assisted S-scheme heterojunction photocatalysts for practical water purification applications.

A solid-state lithium (Li) target for 2.5 MeV, 20 mA proton beam (PB) accelerator boron neutron capture therapy (BNCT) was developed at the Energy Research Institute of Hefei National Comprehensive Science Center (Anhui Energy Laboratory). The Li target must withstand a high heat flux (HHF) of up to 2.8 MV/m2 generated by the PB bombardment. The research team designed an optimized cross-rib structure. To test the thermal removal ability of the structure, electron beam thermal loading experiments verified its effective performance. The results showed that the designed Li target meets the requirement to remove the thermal load generated by the PB (2.8 MW/m2).

In response to the key issues such as poor conductivity, insufficient active sites, and complex preparation processes associated with nickel-iron layered double hydroxide (NiFe-LDH) and iron oxyhydroxide (FeOOH) electrode materials, this study proposed an innovative solution. A one-step hydrothermal method was employed to directly synthesize the NiFe-LDH/FeOOH composite on a 3D nickel foam substrate, and further prepared the NiFe-LDH/FeOOH/graphene oxide (GO) composite. Through a series of physicochemical characterization techniques, the positive effects of GO doping on the microstructure and electrochemical performance of the composites were systematically investigated. The experimental results showed that under the optimized condition with a GO concentration of 0.208 mg mL- 1, the NiFe-LDH/FeOOH/GO composite electrode exhibited excellent electrochemical performance. At current densities of 1, 3, 5, 7, and 10 A g- 1, its specific capacitances reached 1813.3, 1580.7, 1416.7, 1288.3, and 1133.8 F g- 1 respectively, which were significantly superior to those of the NiFe-LDH/FeOOH composite under the same conditions (1726.7, 1495.3, 1341.1, 1218.8, and 1054.4 F g- 1 respectively). In terms of high-current-density performance, at a current density of 10 A g- 1, the capacitance retention rate of the NiFe-LDH/FeOOH/GO composite electrode was as high as 62.5 %, significantly better than the 60.1 % of the NiFe-LDH/FeOOH composite. In the cycle stability test, at a current density of 3 A g- 1, after 1000 charge-discharge cycles, the capacity retention rate of the NiFe-LDH/FeOOH/GO composite was 69.0 %, far higher than the 22.3 % of the NiFe-LDH/FeOOH material. Even after 5000 cycles, although its capacity retention rate dropped to 25.4 %, it was still higher than the 14.4 % of the NiFe-LDH/FeOOH material. The results of this study provided new ideas for the design of supercapacitor electrode materials with high capacity and high-rate performance and made an important contribution to the development of nanoscale energy materials.

Fe-N-C catalysts have emerged as the most promising alternatives to commercial Pt/C catalysts for oxygen reduction reaction (ORR) due to their cost-effectiveness and favorable activity. Herein, a dual-site Fe/FeNx-NC catalyst was synthesized via a green, in situ doping strategy using two-dimensional Fe-doped ZIF-L as a nitrogenrich precursor. The catalyst integrated Fe nanoparticles (NPs) and FeNx sites anchored on carbon nanotubes, intertwined with nitrogen-doped porous carbon nanosheets, achieving a high active site density and graphitisation. Electrochemical tests revealed that the optimized Fe/FeNx-NC-1 exhibited significant ORR activity, with a half-wave potential of 0.92 V and 0.80 V for alkaline and acidic medium, respectively. Zn-air batteries employing Fe/FeNx-NC-1 delivered a peak power density of 168 mW center dot cm-2 and a specific capacity of 790 mAh center dot g-1, outperforming those of Pt-based catalysts. Density functional theory calculations demonstrated a reduced free energy barrier for the rate-determining step (0.48 eV) compared to single-site Fe-N4 models (0.79 eV). The synergy between Fe NPs and FeNx optimized ORR intermediate adsorption and facilitated charge/mass transfer. This study offers valuable insights for the development of advanced energy conversion systems.

The present work focuses on developing a high-performance n-butanol detection system through heterojunction engineering of W18O49/CeO2 nanocomposites, aiming to achieve superior sensitivity and selectivity in volatile organic compound monitoring. The solvothermal-mediated fabrication of CeO2 nanocrystals served as the foundation for hierarchical assembly of the W18O49/CeO2 heterostructured sensing layer. A comprehensive investigation was organized, encompassing discriminative selectivity analysis, durability testing, response profiling, response/recovery characterization under prolonged operational conditions. Experiment confirmed that the W18O49/CeO2 heterojunction sensor achieved peak analytical performance at room temperature, exhibiting a response of 12.2 when exposed with 100 ppm n-butanol. In contrast, the pristine W18O49 had a response of 2.6, and pristine CeO2 showed negligible response. DFT results showed that the adsorption energy of n-butanol on the W18O49/CeO2 composite was -1.092 eV, which was much stronger than that on pristine W18O49 (-0.305 eV), indicating a more favorable adsorption process. Notably, the sensor achieved a detection threshold of 1 ppm n-butanol with a response magnitude reaching 23.5 %, indicating its capability for ultra-trace gas analysis. Collectively, these findings substantiate the W18O49/CeO2 heterojunction architecture as a highly effective sensing platform for volatile organic compound (VOC) detection, with particular applicability to nbutanol gas monitoring in smart manufacturing environments. The superior sensing efficacy stems from the synergistic charge transfer mechanism at the heterointerface, validated by both experimental characterization and theoretical modeling.

To achieve the "double carbon" goal, it is urgent to reform the energy system. The oxygen evolution reaction (OER) is a vital semi-reaction for many new energy-storage and conversion devices. Metal nanoparticles embedded in heteroatom-doped carbon materials prepared by the pyrolyzing of metal-organic frameworks (MOFs) have been a key route to obtain high-performance electrochemical catalysts. Herein, a nanocatalyst embedding Ni nanoparticles into S- and N-co-doped carbon nanoplate (Ni NPs@SN-CNP) has been synthesized by pyrolysis of a Ni-MOF precursor. The prepared Ni NPs@SN-CNP exhibits superior oxygen evolution performance with an overpotential of 256 mV to attain 10 mA cm-2 and a low Tafel slope value of 95 mV dec-1. Moreover, a self-assembled overall-water-splitting cell with Ni NPs@SN-CNP/NF||Pt-C/NF achieves a low potential of 1.56 V at 10 mA cm-2 and a high cycling stability for at least 10 h. The improvement in this performance is benefit from its large surface area, unique morphology, and the nanostructure of the electrocatalyst. This study presents a novel and simple approach to designing high-performance OER catalysts.

Donor-acceptor (D-A) polymers have shown great promise as photocatalysts for hydrogen evolution, benefiting from efficient exciton separation and charge mobility via their push-pull electronic structure. However, despite advantages like cost-effectiveness, synthetic accessibility, and well-defined structures, D-A conjugated small molecules remain underexplored for photocatalytic applications. Herein, three novel D-A-type fulvalene-derived small molecules (F-ID, F-IC, and BF-IC) are synthesized through systematic modulation of donor and acceptor units. Spectroscopic and theoretical investigations revealed that both the extended conjugation length of the donor unit and enhanced electron-withdrawing capability of the acceptor unit can effectively broaden the light absorption range and reduces the optical bandgap. The optimized photocatalyst BF-IC, exhibiting the most red-shifted absorption and narrowest bandgap (consistent with DFT calculations), demonstrated superior photocatalytic performance with a hydrogen evolution rate of 13.43 +/- 0.62 mmol h-1 g-1 using ascorbic acid as the sacrificial agent. To our knowledge, this work presents the first demonstration of highly efficient hydrogen evolution using a fulvalene-derived D-A-type small-molecule photocatalyst. Our study not only establishes fulvalene-based D-A systems as a promising new class of photocatalysts for solar-to-chemical energy conversion but also offers a rational molecular design strategy for high-performance photocatalysts through structural modulation.

Addressing the challenges of weak product selectivity and conversion efficiency for CO2 reduction, this study synthesized a series of K-doped MnO2 nanorod/BiOI nanosheet S-scheme heterojunction catalysts via a hydrothermal hydrolysis method. Under visible-light illumination (lambda > 400 nm) for 12 h, the optimized 30BI/MO-20 catalyst achieved CO and O-2 yields of 278.3 and 101.8 mu mol/g(cat), respectively, with near-complete selectivity for CO. Cycling experiments confirmed stability, and regeneration via hydrothermal treatment effectively suppressed excessive oxygen vacancies. K incorporation not only influenced the CO2 adsorption capacity and oxygen vacancy formation in MnO2 but also enriched the high-energy-level orbitals of the MnO2 band structure, leading to more efficient light-to-chemical energy conversion. The in situ characterization results revealed the S-scheme charge transfer mode, which was mediated by the Mn(IV)/Mn(III) bridge and K-induced band engineering, leading to efficient electron-hole separation and surface reactions. This work provides insights into the design of high-performance photocatalysts for CO2 conversion.

Efficient photocatalysts played a crucial role for degrading phenol pollutants in wastewater and vital for environmental remediation. In this study, a series of novel CaBi6O10/Bi2WO6 (CBO/BWO) step-scheme (S-scheme) heterojunction films were synthesized on the glass substrates through a facile and rapid spraying-calcination method. The CBO/BWO film demonstrated superior visible-light-driven catalytic activity for p-chlorophenol (4-CP) degradation within the fixed-bed photoreactor setup, compared with those of the single-component samples. Typically, the optimal 40CBO/BWO catalyst achieved 4-CP degradation efficiency of approximately 89.5 % after only 60 min under light exposure, attributed to the enhanced visible-light-absorption property and effective charge separation within the S-scheme heterojunction while maintaining high redox abilities among photoinduced carriers. Furthermore, the CBO/BWO catalyst displayed robust resistance to various metal cationic additives. Multiple key intermediates, such as phenol, dihydroxybenzene, benzoquinone and maleic acid, were identified in catalyzing process of 4-CP decomposition via oxidation processes involving hydroxyl radicals and superoxide radical as the primary active species. The above feasible photodegradation mechanism was elucidated and proven. Hence, this work offers valuable insights into developing efficient heterostructure photocatalysts for practical application of environmental remediation.

Facing with the growing demand of wastewater purification in industry and human being, the effect of catalyst on the activation of dissolved oxygen molecule plays a critical role for advanced oxidation processes (AOPs). Surface I atom-doped Bi2WO6 (I-BWO) sheet was successfully synthesized through a two-step hydrothermal method. The decomposition degradation efficiencies of p-chlorophenol and rhodamine B pollutants for the optimized 2I-BWO sample were 14.5 times and 11.0 times than those of the pristine Bi2WO6. The MS results about intermediates explained the mechanism of 4-CP and RhB degradation. Facing with other four organic pollutants such as methylene blue, methyl orange, 4-nitrophenol and tetracycline, the COD removal efficiencies were also observably declined through the photocatalysis. Based on experimental and computational results, the surface I atom caused the disorder of surface structure, forming superior adsorption and activation site of dissolved oxygen molecule. Multiple oxidizing species including superoxide radical, hydroxide radical, singlet oxygen and hydrogen peroxide, were proven to be generated on the modified surface of Bi2WO6 sheet. This study contributes to understanding the impact of in iodine doping on surface structural regulation, thereby facilitating rational design of efficient photocatalysts for AOPs.

Photocatalytic hydrogen evolution from water has been regarded as a green technology for solar energy storage. Fullerene and its derivatives are promising organic photocatalysts due to their isotropic transmission and high electron affinity. However, carrier transfers in fullerene derivatives are hindered by the short exciton diffusion length and lifetime. The heterojunction strategy has been proven to promote exciton separation and improve carrier transport in organic solar cells. Here, we designed and synthesized a hydrophilic conjugated polymer named P4EOBDT-TTE to serve as an additive in fullerene-heterojunction photocatalytic systems. The hydrophilic P4EOBDT-TTE can optimize the heterojunction morphology without requiring additional surfactants, promote charge transfer and enhance exciton dissociation. Using transient and operando photoinduced optical absorption spectroscopies on ps-s timescales, we found that effective exciton separation in the fullerene-heterojunction is achieved through F & ouml;rster energy transfer. By rationally optimizing the addition ratio, the heterojunction photocatalytic system containing 5% P4EOBDT-TTE demonstrated optimal photocatalytic hydrogen evolution activity, reaching 164.32 mmol g-1 h-1, more than 30 times that of pure PC61BM (5.35 mmol g-1 h-1) under the same test conditions (AM 1.5G, 100 mW cm-2 illumination for 5 h), representing one of the highest efficiency for hydrogen evolution with an organic photocatalyst.

Ni and I co-doped TiO2 nanoparticles with mixed anatase-brookite phase (Ni/I-TiO2) were synthesized by the hydrothermal-calcination method for photocatalytic CO2 reduction with H2O vapor. The I and Ni co-doping, anatase-brookite phase junction, as well as the presence of Ti(III) and Ni(III) endowed the catalyst with promoted visible light absorption, increased reduction ability of photogenerated electrons, facilitated charge separation and migration along with modulated CO2 adsorption mode and capacity, ultimately resulting in boosted photocatalytic activity and product selectivity as compared with those of pure TiO2. The CO, CH4 and O2 yields of the optimized Ni/I-TiO2 reached 3.49, 158.25 and 246.30 mu mol/gcat after 15 h of light illumination, which decreased slightly after 9 cycles, and the product selectivity was above 98 % for photocatalytic reduction of CO2 to CH4 with Ni and I co-doping. The in-situ FTIR results with the observation of center dot CH3O and center dot CH3 intermediates confirmed CH4 formation, and the possible mechanism of photocatalytic CO2 reduction over Ni/I-TiO2 was elucidated. This work provides new insights to pursue efficient catalysts for the selective photocatalytic CO2 reduction to CH4.

The photocatalyst film, composed of tetragonal BiOI nanosheets and cubic phase CuI nanoparticles, was synthesized on the FTO substrate by a simple electro-deposition method. The orderly crisscrossed nanosheet structure caused exterior hydrophobic property, resisting the excess H2O 2 O molecules and further inhibiting the competitive H2O 2 O reduction process. The novel BiOI/CuI catalyst exhibited excellent photocatalytic ability of CO2 2 reduction into CO with 100 % selectivity in H2O 2 O vapor. Typically, the optimal 150BiOI/CuI photocatalyst exhibited CO yield of 7237.65 mu mol/cm2 2 after 11 h of simulated sunlight illumination, achieving quantum efficiency of 2.5 % at 380 nm. The excellent performance of the BiOI/CuI composite film in photocatalytic CO2 2 reduction can be attributed to the construction of hydrophobic surface and S-scheme heterojunction with I 3- /I-- redox mediator, as confirmed by the in-situ XPS, hole injection test and cyclic voltammetry results. This study lays the groundwork for employing highly efficient iodide-based photocatalysts in gas-liquid-solid triphase catalytic systems.