Preparation Of Cuprous Oxide-based Heterostructure And Study On The Performance Of Photoreduction Of Carbon Dioxide

With the rapid development of global industrialization and the continuous growth of the world’s population,the demand for energy is increasing,and now the main way to obtain energy is to burn a large amount of non-renewable fossil fuels,which also causes excessive emissions of carbon dioxide（CO₂）.Therefore,finding green,resource-rich,renewable and clean energy and fixing or converting CO₂ provide an efficient strategy to solve this problem.Converting CO₂ into energy fuels such as methanol（CH₃OH）or high value-added fine chemicals through artificial photosynthesis can maximize the recovery and reuse of carbon dioxide,and can also alleviate energy and environmental problems,while helping to achieve"double carbon""Target.Due to the abundant reserves and low price of metallic copper,copper and its derivatives are currently widely used in the photoreduction of CO₂ into energy fuels.However,the photoinduced electron-hole recombination rate and photostability are the main obstacles to its large-scale practical application.Based on this,this paper mainly carried out the following researches:1.U-Cu₂O-PCN heterojunction for CO₂ photoreduction in pure water.In order to improve the photostability of cuprous oxide（Cu₂O）and speed up the separation of photogenerated electrons and holes,polymeric carbon nitride（PCN）with wide band gap and high stability and ultrafine cuprous oxide（U-Cu₂O）were used to construct composite material.In this thesis,we synthesized U-Cu₂O on PCN by exploiting the confinement topological transition properties of layered trimetal hydroxides to construct a novel Z-type photocatalyst（U-Cu₂O-PCN）,which solves the problem of Cu₂O self-light The problem of corrosion and the low activity of PCN for photoreduction of CO₂.In the pure water system,without additional sacrificial agent and photosensitizer,using U-Cu₂O-PCN as photocatalyst,the formation rate of CH₃OH reaches 51.22μmol g^-1 h^-1,realizing the efficient catalytic conversion of CO₂to CH₃OH.What’s more,the catalytic activity of the material remained above 96%after 5 cycles of reaction.It provides a new idea for realizing the efficient photocatalytic conversion of CO₂ to CH₃OH in pure water.2.Preparation of Cu₂O@ZnCr-LDH heterostructures and photoreduction of CO₂to methanol.Cu₂O has a suitable band gap and high electrical conductivity,which can absorb visible light and generate high-energy electrons for photoreduction of CO₂（PCO₂RR）,which makes it a very potential photocatalytic CO₂ reduction material,but the fast recombination of photogenerated carriers and the serious photolithography itself limits its practical application in the field of photocatalysis.In this study,a novel Z-type photocatalyst（Cu₂O@ZnCr-LDH）was constructed by in situ growth of layered double hydroxides（ZnCr-LDH）on the surface of Cu₂O using the Lewis acid-base theory using Cu₂O as a template.The performance of photocatalytic carbon dioxide reduction to methanol was studied.