Synthesis Of Novel Photocatalyst And Application In Photocatalytic Reduction Uranium(?)

Nuclear power as a carbon-free energy or fusion energy,is one of the most potential energy for solving the world energy crisis and environmental pollution problems.However,with the rapid development of the nuclear industry,large amounts of radioactive wastewater discharge,which seriously threaten human health and ecological security.As the main raw material of nuclear energy,uranium becomes the first radioactive pollutant that needs to be controlled.In this regard,semiconductor-based photocatalytic reduction could be newly-developing,higher-performance and environmentally friendly technology for U???removal from aqueous solution.However,most conventional photocatalysts are inefficient and cannot meet the requirements for practical application.In this paper,Sn-doped In₂S₃photocatalysts were obtained for high efficiency removal of U???.Besides,we successfully synthesized a novel tin oxysulfide?SnOS?photocatalyst.The structure,composition,morphology and optical properties of two kinds of photocatalyst were characterized by using X-ray diffraction?XRD?,UV–vis diffuse reflectance spectra?DRS?and other various analytical techniques.And their performance of photocatalytic reduction uranium???under visible light irradiation were researched.The main research contents are as follows:?1?A series of Sn-doped In₂S₃ microspheres photocatalyst were synthesized by a simple hydrothermal method.Determined by various analytical and spectroscopic techniques,it implied that Sn⁴⁺cations were incorporated into the In₂S₃ lattice,formed the hierarchically porous structure and yield greater specific surface area.Compared with pure In₂S₃,the samples doped with moderate amounts of Sn exhibited greater photocatalytic activities in reduction of U???under visible light irradiation.The optimum Sn-In₂S₃ photocatalyst with Sn:In molar ratio of 1:4.8?Sn-In₂S₃?had the highest photocatalytic performance and 95%of U???was reduced after 40 min of visible light irradiation,which was 15.60 times faster than that of pure In₂S₃.When the pH was 6 and the dark adsorption time was 1h,the photoreduction of U???was fastest than other cases.The structure of Sn-In₂S₃ remained stable after recycling run.The enhanced photocatalytic performance of Sn-In₂S₃ could be attributed to the higher specific surface area,stronger absorption of light,the narrowed band gap and the efficient separation of photogenerated electron-hole pairs?e^-/h⁺?.Furthermore,the possible enhanced photocatalytic mechanism was also investigated.?2?The novel SnOS photocatalytic adsorbent was successfully synthesized by a facile solvothermal method.Interestingly,the as-prepared SnOS possessed not only superior adsorption performance,but also outstanding photocatalytic ability for the reduction of U???.Employing SnOS as adsorbent,the adsorption processes can be described via Langmuir isotherms and pseudo-second-order mode.And the maximum Langmuir adsorption up to321.64 mg/g.The high capacity for adsorption of U???was mainly responsible for its large specific surface area,surface complexation electrostatic interactions and surface complexation.When the pH was 6 and the dark adsorption time was 120min,the corresponding photoreduction efficiency of U???was 55%after the 180 min irradiation of visible light.Benefitted from the strong synergy between adsorption and photocatalysis,the total U???removal was 95%over SnOS.Besides,SnOS was relative stable and exhibited good recyclability in the photocatalytic process,which may have practical application.This study provide theoretical basis for design a novel photocatalyst in future.