G-C₃N₄ Based Nano Heterojunction And Its Photocatalytic Hydrogen Production Research

In recent years,as the global fossil fuel consumption increased year by year,the energy shortage and environmental pollution problems have been mentioned more and more.The demand for new green renewable energy is becoming increasingly urgent.So looking for new green energy research has been the focus of the world's governments and scientists.Hydrogen is generally thought to be an ideal two energy without pollution.In the existing methods of producing hydrogen,the hydrogen is considered to be one of the most promising hydrogen production methods by using semiconductor materials to produce hydrogen.However,there are still some problems need to be solved in the field of photocatalytic hydrogen production.One of the most important problems is to improve the hydrogen production performance of semiconductor photocatalyst.In order to improve the photocatalytic hydrogen production performance,you need to start from the three aspects:how to improve the light absorbing material,how to make light generated carriers separation as soon as possible to prevent the composite and how to make the catalyst surface reaction can be carried out smoothly.This paper attempts to prepare graphite phase carbon nitride,which is the g-C₃N₄ based composite photocatalyst,hoping to solve the above two problems to improve the performance of g-C₃N₄ photocatalytic hydrogen cracking.Specific work is as follows:Dicyandiamide as precursor,g-C₃N₄ was prepared by polycondensation.The dispersion of g-C₃N₄ nanosheets was obtained by ultrasonic liquid phase separation method,and the properties of the composite were studied by using the dispersion as the base material.Using sol-gel method,using isopropyl titanate as raw materials,isopropyl titanate is added to the g-c3n4 nanosheets dispersed liquid,g-C₃N₄/TiO₂ composite and formed between the two groups using a heterojunction.Improve the photoinduced charge separation efficiency,in order to improve the catalytic efficiency.In addition,the MoS₂ dispersion was obtained by ultrasonic liquid phase separation,and the g-C₃N₄/MoS₂ composites were prepared by mixing the two kinds of dispersion.In this paper,a variety of characterization methods were used to characterize the product.Such as powder X-ray diffraction analysis?XRD?,ultraviolet visible absorption spectroscopy?UV-VIS?,photoluminescence?PL?spectroscopy,scanning electron microscopy?SEM?methods,and through the light catalytic cracking hydrogen production from water test and Research on the performance of the photocatalytic performance of.Experiments show that compared with the original g-C₃N₄,under UV visible light irradiation,the composite has higher photocatalytic hydrogen production activity,show that the heterojunction indeed promote the photogenerated electron hole separation,and MoS₂ can broaden the range of light absorption and improve the energy utilization rate.For composites,there exists an optimal mass ratio between the two components to achieve the best performance.