Preparation Of Stable Structure Golded Supportted Carbon Nitride Catalyst And Photosynthesis Of Hydrogen Peroxide

Hydrogen peroxide?H₂O₂?,a mild and environment-friendly oxidant has been used as a green chemical and applied in a variety of industrial and living aspects,such as papermaking,water treatment,chemical synthesis,disinfection and sterilization.In addition,H₂O₂ is a promising liquid fuel for H₂O₂-based fuel cell because only water is emitted.Compared to the widely known fuel H2,H₂O₂ is easier to be stored and is more convenient to be transported with a low risk of usage.The current industrial production of H₂O₂ is based on an anthraquinone method.The advantages are scale-up and high productivity of H₂O₂.However,huge energy consumption,complicated by-products and safety issues are still challenges.It is highly desirable to pursue an efficient,mild and sustained way as an alternative for synthesis of H₂O₂.It is a great challenge to design high performance catalysts to improve H₂O₂ production and control product selectivity.The graphitic phase carbon nitride?g-C₃N₄?,a polymeric layered material,has been explored as a photocatalyst for pollutant decomposition and water splitting because of its relatively narrow bandgap??2.7 eV?and suitable valence band and conduction band levels.Recently,C₃N₄-based materials have been utilized in light synthesis of H₂O₂.The key to further development of higher performance catalysts is to regulate the surface properties of C₃N₄ by some suitable methods to improve the production of H₂O₂ and the selectivity of catalytic reaction.In this paper,we focus on the design of photocatalyst for the synthesis of H₂O₂.The main results are as follows:we prepared a Au-supported C₃N₄ catalyst i.e.,Au/C₃N₄-500?N₂?by strongly anchoring Au nanoparticles??5 nm?onto C₃N₄ matrix,which simultaneously enhances the activity towards photo-synthesis of H₂O₂ and the stability when reused.The yield of H₂O₂ reached 1320 ?molL^-1 on Au/C₃N₄-500?N₂?after 4hr light irradiation in an acidic solution?pH=3?,higher than that(1067 ?molL^-1)on the control sample Au/C₃N₄-500?Air?and 2.3 times higher than that on the pristine C₃N₄.Particularly,the catalyst Au/C₃N₄-500?N₂?keeps much higher stability.The yield of H₂O₂ has a marginal decrease on the spent catalyst i.e.,98%yield is kept.In comparison,only 70%yield is obtained on the spent control catalyst.The robust anchoring of Au onto C₃N₄ improves their interaction,which remarkably decreases the Au leaching when used and avoid the aggregation and grown-up of Au particles.Little Au leaching was detected on the spent catalyst.The kinetic analyses indicated that the highest formation rate of H₂O₂ isachieved on the Au/C₃N₄-500?N₂?catalyst.The decomposition tests and kinetic behaviors of H₂O₂ were also carried out.The findings suggest that the formation rate of H₂O₂ could be a determining factor for efficient production of H₂O₂.