Preparation Of Cu₂?OH?PO₄ And Its Photocatalytic Reduction Of Wastewater Containing Uranium

With the continuous development of society and the continuous depletion of energy,nuclear energy,as a new energy technology,will play a more important role in today's society.However,a large amount of uranium-containing waste water is generated during the mining and smelting of uranium ore,which has strong chemical toxicity and radioactivity,The threat to the natural environment and human health becomes increasingly severe,and it has become an important issue that restricts the development of nuclear energy.Therefore,there is an urgent need for an efficient,clean and sustainable technology to solve the pollution problem of uranium-containing wastewater.Under this background,the photocatalytic technology of semiconductors represented by TiO₂ is based on the characteristics of no secondary pollution and high efficiency.It has become a new uranium-containing wastewater treatment technology with research value and development prospects.However,the application is limited by the existing photocatalytic materials have disadvantages such as low solar energy utilization and high electron-hole recombination rate.Therefore,the search for a photocatalytic material with high visible light activity is the key to solve the pollution problem of waste water containing uranium.In order to solve the above problems,based on summarizing the current research status of photocatalytic materials at home and abroad,electron-hole-releasing,visible-light-responsive copper-hydroxyphosphate?Cu₂?OH?PO₄?is selected by this study as the research object,from the relationship between structure and properties,the photocatalytic reduction rate of uranium-containing wastewater is improved through microstructural regulation and carbon quantum dot?CDots?modification;combined with XRD,SEM,Uv-vis,XPS,and PL spectra.Such characterization methods explored the photocatalytic reduction mechanism of Cu₂?OH?PO₄ and the synergistic mechanism of CDots.The specific findings are as follows:?1?Using Cu?NO₃?₂ and?NH₄?₂HPO₄ as raw materials,a visible light-responsive photocatalytic material Cu2?OH?PO₄ is prepared by hydrothermal method and applied in photocatalytic reduction of uranium-containing wastewater.The results show that the preferential growth and crystallinity of the{011}and{101}planes are the key factors influencing the photocatalytic performance of Cu₂?OH?PO₄;selecting suitable preparation conditions,the microstructure of Cu2?OH?PO4 is controlled and the remove rate of uranium-containing wastewater reached 71.19%by optimizing the reduction conditions..In combination with XPS,Uv-vis,and other characterization methods,the photocatalytic reduction mechanism of Cu₂?OH?PO₄ is given:the Octahedron of Cu²⁺photogenerated electron generate metastable Cu⁺,E_Cu?II?/Cu?I?has lower reduction electromotive force than E_U?VI?/U?IV?,and can reduce U?VI?to U?IV?.?2?In order to further improve the photocatalytic activity of Cu₂?OH?PO₄,a novel visible light-responsive photocatalytic material Cu₂?OH?PO₄ is synthesized by one-step hydrothermal method using CDots and applied to photocatalysis,and applied it to photocatalytic reduction of uranium-containing wastewater.The results show that the modification of CDots can increase the absorption capacity of Cu₂?OH?PO₄ in the visible range and promote its visible light response.At the same time,CDots can provide an easier path as an electron transfer body,which accelerates the speed of electron migration and improves its photocatalytic activity;By optimizing the preparation and reduction process conditions,the remove rate of uranium-containing wastewater can reach 90.02%.