| In 1972,Fujishima has discovered that titanium dioxide can be used for hydrogen evolution by photocatalysis technology;since then,titanium dioxide has become the most attractive candidate for addressing the problems of environmental pollution and energy shortages.The disadvantage is that the unique energy band distribution of titanium dioxide itself makes it unsatisfactory in the conversion of solar energy.Graphite C3N4（g-C3N4）photocatalyst is a promising candidate because it has many advantages such as chemical stability and low cost.However,g-C3N4 has a relatively low surface area due to the layered stacking between its layers and strong van der Waals forces,which limits the formation of active sites and increases the charge recombination rates.The researchers found that the effective combination of the two materials g-C3N4and phosphide can effectively improve the above shortcomings.In this paper,mesoporous g-C3N4（Meso-g-C3N4）was synthesized by the hard template method.Ag/CoxP/Meso-g-C3N4 heterojunction photocatalyst was prepared by using monocyandiamide and cobalt nitrate as precursors and adopting high-temperature calcination and photoreduction strategies.The prepared WP was added to the precursor,and it was calcined at high temperature by ultrasound.3D mesoporous Meso-g-C3N4/WP/Meso-g-C3N4 sandwich heterojunction photocatalyst was prepared by the method.Analysis of two materials by a series of test methods.At the same time,ceftazidime and phenol were used as degradation substrates to evaluate the degradation activity of synthetic photocatalysts.In addition,the photocatalyst’s hydrogen splitting activity under water was tested.The research results of this article include:（1）By adjusting the mass ratio of CoxP and Meso-g-C3N4,Ag/CoxP/Meso-g-C3N4photocatalyst was prepared by ball milling and photoreduction.The test results show that the heterojunction structure that has been formed between Ag/CoxP/Meso-g-C3N4can effectively improve the separation efficiency of charge and is beneficial to the rapid progress of photocatalytic reactions.(The degradation rate of ceftazidime is 92%,and the rate of hydrogen production by photocatalytic decomposition of water is 96.66μmol h-1g-1)（2）3D Meso-g-C3N4/WP/Meso-g-C3N4 interlayer heterojunction nanosheets were synthesized by using monocyandiamide and ammonium tungstate as precursors through the methods of ultrasound and high temperature calcination.The characterization results show that this special heterojunction structure can effectively improve the photocatalytic activity.Under visible light irradiation,the degradation rate of phenol by Meso-g-C3N4/WP/Meso-g-C3N4 is as high as 98%,and the rate of hydrogen production by photocatalytic decomposition of water is 198.1μmol h-1g-1. |
