Preparation Of Carbon-based Materials And Study On Its Photocatalytic Performance Of Hydrogen Peroxide Synthesis

Hydrogen peroxide（H₂O₂）is a very promising liquid fuel because of the advantages of high energy density,zero-pollution and convenient storage.As the feed of H₂O₂fuel cell,H₂O₂only yields O₂and H₂O as byproducts.Traditional methods for the preparation of H₂O₂result in high energy-consumption,toxic by-products and high production risk.The development of new environmentally friendly and low-cost methods to produce H₂O₂is highly desirable.The use of solar energy for the catalytical conversion of H₂O to H₂O₂is a green and low-cost preparation technology.However,the weak light absorption capacity,severe charge recombination and poor stability of the conventional photocatalyst limit the yield of photocatalytic H₂O₂.In this study,gold-supported phosphating carbon nitride（Au/P/g-C₃N₄）and carbon solid acid materials have been prepared,and the photocatalytic performance and the mechanism are evaluated and discussed.Firstly,graphite phase carbon nitride（g-C₃N₄）is prepared by high-temperature sintering method.Then gold-supported carbon phosphide nitride（Au/P/g-C₃N₄）is prepared and its structure and properties were studied.The results show that the band gap of g-C₃N₄is 2.80 e V,while the band gap of Au/P/g-C₃N₄is 1.92 e V,indicating that the simultaneous incorporation of gold and phosphorus can significantly improve the light absorption capacity of g-C₃N₄.It was found by electrochemical studies that the synergistic effect of gold and phosphorus results in the lower charge transfer resistance of the composite photocatalyst Au/P/g-C₃N₄than that of g-C₃N₄and Au/g-C₃N₄,and thus the catalytic activity is significantly enhanced.The photocatalytic production of H₂O₂from H₂O is 151.3μmol g^-1h^-1,which is 26 times higher than that of the pristine g-C₃N₄.This work provides new insight for the rational design of new photocatalysts.The carbon solid acid photocatalyst is prepared by one-step hydrothermal method using furan formaldehyde as the raw material.The influence of the hydrothermal reaction temperature on the morphology,structure and photocatalytic performance from seawater are investigated.The results show that the catalytic performance of the carbon solid acid gradually improves and subsequently decrease with the increased hydrothermal reaction temperature.The carbon solid acid prepared at 160℃has the best catalytic performance,obtaining a production rate of 1971μmol g^-1h^-1for the photocatalytic conversion of H₂O₂from seawater.Further study has found that the carbon solid acid prepared at 160℃has the strongest light absorption capacity,the lowest photo-generated carrier recombination and transfer resistance.This work provides a new solution for the development of high-efficiency,low-cost and stable novel catalysts for the production of H₂O₂from seawater.