Controllable Liquid-phase Synthesis And Hydrogen Production Performance Of Noble Metal-free Cocatalyst For The Enhanced Photocatalytic Activity Of G-C₃N₄

As a sustainable green energy production technology,photocatalytic H₂production is the most effective strategies to solve the current energy problems.Photocatalytic degradation of pollutants is a simple and environment-friendly way of treatment,which has become a global research topic.Some precious metal materials can achieve the expected effect,with the high cost and difficult to load.In this paper,we propose to prepare high-efficiency non noble metal co-catalyst/g-C₃N₄ material.In this paper,three kinds of non noble metal co-catalyst/g-C₃N₄ composite were synthesized by changing reactants and experimental conditions.The photocatalytic activities of composites were tested and proved to have high efficiency and stability.The photocatalytic degradation mechanism was explored by using a variety of different capture agents.The specific work is as follows:A hydrothermal method was used to synthesize hollow Ni_xCo_1-xS/g-C₃N₄materials.The composite has better photocatalytic hydrogen production and degradation performance.The optimized 4 wt%Ni_xCo_1-x-x S/g-C₃N₄ composite has the maximum hydrogen generation rate,which is 1420?mol·g^–1·h^–1.The degradation rate of Ni_xCo_1-x-x S/g-C₃N₄ to methyl orange?MO?reached 98.14%in 9 min.We proved the high stability of the photocatalysis material through the experiment of hydrogen production and degradation cycle.At the end of the paper,we explored the photocatalysis mechanism of the material.Because the material has a unique hollow structure,which can provide convenient charge transfer channels,promote the separation and transmission of electron-hole pairs,and show excellent photocatalytic performance.The NiSe/g-C₃N₄ was prepared by a hydrothermal method,and its photocatalytic hydrogen production and degradation of methyl orange?MO?were tested.The H₂production efficiency of 3 wt%NiSe/g-C₃N₄ is 1250?mol·g^–1·h^–1,and the degradation rate is 92.25%in 5 min.After 5 cycles of degradation,the material still shows good stability.At the end of Chapter 4,the mechanism of photocatalysis is proposed,which helps us to understand the photocatalysis process.The non noble metal NiCoP/g-C₃N₄ composite was successfully prepared and proved to have excellent photocatalytic performance,among which the hydrogen production performance of the composite is 126 times of the g-C₃N₄,and the degradation activity is 97.35%in 6 min.The photocatalytic stability of the composite was proved by cyclic hydrogen production and degradation experiments.It shows that NiCoP can be used as a cocatalyst to improve the photocatalytic activities.In this paper,an effective and economical synthesis method is proposed,and profound opinions on the control of photocatalytic performance are put forward.The relationship between electron and material properties is studied and explained in-depth,friendly environment and excellent performance,the design of cocatalyst to improve the activities of composites,promotes the research of photocatalysis to enter a new stage,and has great significance in the field of environmental protection and energy.