Construction Of Photocatalyst Based On Strontium Zirconate And Its Application In Photocatalytic Water Splitting

Fossil fuels are the basis of the development of modern society.However,they are a kind of non-renewable resource,and can cause serious environmental pollution and ecological damage because of their improper exploitation and usage.Hydrogen has attracted extensive attention due to its high calorific value,water as combustion product and no pollution.The photocatalytic decomposition of water by utilizing the inexhaustible sunlight is considered to be a fundamental solution to solve the environmental pollution and energy crisis facing humanity.In the past decades,great progress has been made in photocatalytic research,but it is still difficult for the photocatalytic efficiency to meet the requirements of commercial applications.Photogenerated electrons and holes are easily recombined,which is one of the reasons for their low photocatalytic efficiency.SrZrO₃ is a perovskite photocatalyst.And it has been widely used in fluorescent materials,sensors,etc.,but there are few studies on photocatalysis.In this paper,based on SrZrO₃ materials,the mechanism of photocatalytic hydrogen production and oxygen production was studied by constructing heterostructure materials with g-C₃N₄ and WO₃.Then it can be divided into four parts:The first chapter is the introduction,which mainly reviews the research progress in the field of photocatalysis in recent years,and focuses on the application of perovskite semiconductor materials and g-C₃N₄,WO₃ in the field of photocatalysis.In the second chapter,SrZrO₃ is a typical perovskite structure semiconductor material with a band gap of 5.25 eV,which can only respond to light with a wavelength of 200-400 nm,and photogenerated electrons and holes are easily recombined.In order to solve this problem,we simply mixed and calcined it with g-C₃N₄ material to construct g-C₃N₄/SrZrO₃ composites,and studied its hydrogen production activity under ultraviolet and all-light conditions.We found that the electrons on the conduction band of SrZrO₃ can be transferred to the conduction band of g-C₃N₄ through interface contact,which expands the spectral absorption range,promotes the separation of electrons and holes,and improves the hydrogen production efficiency of photocatalytic water splitting.In the third chapter,WO₃ is one of the most widely studied oxygen-producing photocatalysts because of its wide spectrum absorption range and suitable band gap.However,it has no hydrogen-producing property,that is,it does not have the ability to photolyze water,while the hydrogen-producing property SrZrO₃ is well.In view of this,we synthesized SrZrO₃/WO₃composite photocatalyst by one-step calcination method,and studied its hydrogen production and oxygen production efficiency under all-light.The result shows that the oxygen production activity of WO₃ catalyst and its photocatalytic efficiency has been greatly improved after the combination of the two catalysts.The fourth chapter gives a brief summary and outlook on the full text.