Enhancing Photocatalytic Hydrogen Evolution through Electronic Structure and Wettability Adjustment of ZnIn_(2)S_(4)/Bi_(2)O_(3) S-Scheme Heterojunction

The production of renewable fuels through water splitting via photocatalytic hydrogen production holds significant promise.Nonetheless,the sluggish kinetics of hydrogen evolution and the inadequate water adsorption on photocatalysts present notable challenges.In this study,we have devised a straightforward hydrothermal method to synthesize Bi_(2)O_(3)(BO)derived from metal‐organic frameworks(MOFs),loaded with flower-like ZnIn_(2)S_(4)(ZIS).This approach substantially enhances water adsorption and surface catalytic reactions,resulting in a remarkable enhancement of photocatalytic activity.By employing triethanolamine(TEOA)as a sacrificial agent,the hydrogen evolution rate achieved with 15%(mass fraction)ZIS loading on BO reached an impressive value of 1610μmol∙h^(−1)∙g^(−1),marking a 6.34-fold increase compared to that observed for bare BO.Furthermore,through density functional theory(DFT)and ab initio molecular dynamics(AIMD)calculations,we have identified the reactions occurring at the ZIS/BO S-scheme heterojunction interface,including the identification of active sites for water adsorption and catalytic reactions.This study provides valuable insights into the development of high-performance composite photocatalytic materials with tailored electronic properties and wettability.

Novel BiOBr/Bi2S3 high-low junction prepared by molten salt method for boosting photocatalytic degradation and H_(2)O_(2)production

The molten salt method focuses on improving the crystallinity of synthetic materials and avoiding the high energy consumption of traditional synthesis processes.In this work,a novel BiOBr/Bi_(2)S_(3)high-low junction with large contact area was constructed by the molten salt method combined with the ion exchange strategy.Its unique energy band structure and new charge transfer mechanism realize the rapid migration of photogenerated charges between different components.Specifically,Bi_(2)S_(3)was grown on BiOBr in situ by a high-temperature molten salt reaction.Due to the deep valence band position of BiOBr and the narrow band gap of Bi_(2)S_(3),an intrinsic internal electric field and band bending are produced at the interface,forming a high-low junction photocatalyst with an intimate interface.In addition,the BiOBr/Bi_(2)S_(3)composite maintains a high oxidation potential and produces high and robust photocatalytic oxidation activity.In the molten state,the close binding of BiOBr and Bi_(2)S_(3)can be promoted through the ion-exchange strategy,resulting in excellent photocatalytic degradation rates of bisphenol A and tetracycline and in-situ generation of H_(2)O_(2).Finally,the mechanism of carriers separation and transfer in BiOBr/Bi_(2)S_(3)high-low junction is also discussed.Density functional theory(DFT)results found that the improvement of O_(2)adsorption ability would promote the occurrence of oxygen reduction reaction(ORR),and make positive contributions to the enhanced H_(2)O_(2)production activity.This study will provide a new perspective for broadening the spectral response range of Bi-based photocatalytic materials and preparing high-low junction photocatalysts with dense interface by the molten salt method.