Study On The Modification Of Graphite Phase Carbon Nitride Composites And Their Application In Photocatalytic Hydrogen Production

In the 21st century,with the continuous and rapid development of industrialization and urbanization,the energy demand is increasing,so the problems of continuous large-scale consumption of fossil fuels,environmental degradation and energy shortages have become increasingly serious,which has seriously threatened human health and life.At the same time,it also restricts the advancement and development of society,and has become a problem that needs to be urgently solved in the world today.Solar energy is an environmentally friendly and inexhaustible green energy source.By fully utilizing solar energy through photosynthesis,it is converted into the chemical energy we need,which can solve serious problems such as environmental pollution and resource shortage.Is the direction we need to work hard to explore.Photocatalysts are essential in the conversion of solar energy to chemical energy.In 1972,TiO₂was used as a photocatalytic material for hydrogen and oxygen production.Since then,semiconductor photocatalytic materials have been extensively studied by scientific researchers.Semiconductor photocatalytic technology,as a green safety technology capable of converting solar energy into chemical energy,has great development prospects in terms of controlling environmental pollution and solving energy shortages.Photocatalyst is indispensable in the process of converting solar energy into chemical energy.Graphite phase carbon nitride is a non-metallic semiconductor with relatively simple synthesis process,abundant earth reserves,non-toxic and harmless,and strong chemical stability.Photocatalysts have attracted widespread attention from researchers in the field of photocatalytic water splitting in recent years.Because of its special electronic optical structure and excellent chemical stability,and the band gap can reach 2.7 eV,it is very conducive to the absorption of visible light.In the use of solar energy to degrade organic pollutants,photolysis of water to produce hydrogen,photolysis of CO₂ light,it has great application prospects in many fields such as detoxification of harmful gases and sensors.However,due to its small specific surface area,it is easy for recombination of photogenerated electrons and holes to occur,so the photocatalytic activity of the catalyst is inhibited to a certain extent.For the graphite-phase carbon nitride semiconductor photocatalyst,the simple and feasible method of doping can greatly reduce the probability of recombination of photo-generated electrons and holes,thereby improving its utilization efficiency of sunlight and its efficiency.Photocatalytic hydrogen production performance.In addition,the morphology of graphite phase carbon nitride can be effectively adjusted to increase its specific surface area,provide more reactive sites,and effectively inhibit the recombination of photo-generated electrons and hole pairs to achieve graphite.The purpose of enhanced carbon nitride catalytic activity.The research in this paper is mainly divided into the following contents:In the first part,the graphite phase carbon nitride was modified by transition metal ion doping.Using NiCl₂·6H₂O and melamine as raw materials,composite graphite-phase carbonitride catalysts with different Ni doping contents were synthesized by pyrolysis.The results show that the photocatalytic activity is significantly improved by doping.The photocatalytic hydrogen production test and a series of characterizations of the morphology and structure of graphite phase carbon nitride with different Ni doping amounts were compared to obtain the optimal Ni doping amount?m?Ni?:m?melamine?=1.2%?.In the second part,the morphology of graphite phase carbon nitride is effectively controlled.We synthesized a carbon nitride precursor by a simple hydrothermal method,and further synthesized a carbon nitride catalyst with a bubbly appearance through further reflow and calcination,and deposited this catalyst to 1wt%Pt and different contents of Ni were tested for their hydrogen-producing activity under all light and visible light.The results show that the bubble-like carbon nitride synthesized has significantly improved photohydrolytic hydrogen production activity.