Influence And Mechanism Of Support Surface On Photocatalytic Water Splitting For Hydrogen Production

Rapid urbanization and industrialization have led to global energy shortage,and a large number of harmful and toxic chemical pollutants have been discharged into the environment.In order to solve the above-mentioned environmental and energy crisis,it is necessary to conduct research on clean and renewable energy.Among the existing options,the conversion of solar energy into chemical fuels has been favored by more and more researchers in recent decades.Among them,the semiconductor photocatalytic water decomposition technology driven by visible light is considered as one of the most promising strategies to overcome the challenges of environmental pollution and global energy shortage.The construction of photocatalyst is more important in photocatalytic water decomposition to produce hydrogen.The support is an important part of the supported photocatalyst,which is the key factor affecting the photocatalytic performance,so the research on the the support is more important.In this article,Al₂O₃ with different hydroxyl contents（AO,AOH,AOH200,AOH500 and AOH800）were used as supports,and Pt and CdS were loaded.CdS/Pt/AO,CdS/Pt/AOH,CdS/Pt/AOH200,CdS/Pt/AOH500 and CdS/Pt/AOH800 were prepared,respectively.The influence of hydroxyl content of the support on the photocatalytic water decomposition was studied through the characterization of phase,morphology,composition and photoelectrochemical properties.The photocatalytic hydrogen production experiments show that CdS/Pt/AOH prepared by AOH has the best photocatalytic activity(2524.99μmol h^-1)under visible light irradiation,and the quantum efficiency is up to 46.3%at 460 nm wavelength.Through the characterization of phase,morphology,composition and photoelectrochemical properties,it is found that OH on AOH can promote the separation of photoelectron-hole pairs and the removal of O atoms generated by the decomposition of H₂O,release more catalytic active sites to generate H₂,and inhibit the recombination of H and O atoms.Photocatalysts CdS/Pt/LSPB and CdS/Pt/BS-02 were constructed by using low-sodium quasi-boehmite（LSPB）and boehmite（LSPB）with similar structure as supports and supporting Pt and CdS.The hydrogen production activity of the catalysts was studied.The results show that:the hydrogen production activity of CdS/Pt/LSPB(2553.55μmol h^-1)was much higher than that of CdS/Pt/BS-02(1331.71μmol h^-1).By analyzing the phase,composition,morphology and photoelectric chemical properties of the two kinds of support and the prepared catalyst,it is found that the specific surface area of the support has a great influence on the activity of hydrogen production.