Preparation Of ZnO-based Heterojunction Photocatalytic And It’s Desulfurization Performance

With the pollution of the environment,photocatalytic technology has attracted extensive attention.Catalytic oxidation degradation of pollutants is particularly important.As a stable,non-toxic and inexpensive semiconductor material with good physical and chemical properties,ZnO has strong photocatalytic performance and shows broad application prospects.As a direct band gap semiconductor,ZnO can only absorb the ultraviolet light,while ultraviolet light only accounts for 6%-8%of sunlight.Therefore,improving the visible light response of ZnO is the core problem to solve the practical application.In this paper,ZnO was used as the substrate to prepare heterostructures.The FCC simulated gasoline was used as the degradation material to study the photocatalytic properties of different heterojunction materials.First,A ZnO/WO₃ heterojunction photocatalyst was prepared by a two-step method.The crystal composition and morphology were characterized by XRD,XPS,SEM and HRTEM.The optical and optoelectronic properties were characterized by UV-Vis-DRS,PL and photoelectrochemistry.From the SEM and TEM results,WO₃ was loaded onto ZnO in the form of microchips,and the surface roughness of ZnO increased.The activity of ZnO/WO₃ were investigated by photocatalytic oxidative simulating FCC gasoline（thiophene in n-octane solution）.The results show that WO₃ was compounded on the surface of ZnO,which was beneficial to the separation of photogenerated electrons and holes,and significantly improved the stability of photocatalyst.After 150 min of visible light irradiation,the photocatalytic oxidation desulfurization rate of ZnO/WO₃ could reach 75.99%,and the desulfurization rate could still reach about 62%after 5 cycles of recycling.Second,ZnO/Ag₃PO₄ heterojunction catalyst was obtained by hydrothermal method and in situ precipitation method,and crystal structure,microstructure,optical and photoelectric properties were analyzed.The photocatalytic oxidation desulfurization performance of ZnO/Ag₃PO₄ heterojunction was studied.The results show that ZnO/Ag₃PO₄ heterojunction have good crystallinity,and the presence of Ag₃PO₄ greatly broadened the light response of ZnO.After 120 min of light irradiation,the desulfurization rate was 84.1%,which was significantly better than that o ZnO（54.01%）and Ag₃PO₄（45.22%）.Third,Z-type ZnO/MoS₂ heterojunction catalyst was obtained by hydrothermal method and in-situ precipitation method.The photocatalytic oxidative desulfurization activity of ZnO/MoS₂ was investigated.The results show that MoS₂ dispersed on ZnO in the form of nanosheets,which increased the specific surface area and the adsorption capacity,and effectively improved the separation of photogenerated electrons and holes.After 150 min of irradiation,the photocatalytic desulfurization rate of ZnO/MoS₂ reached95.52%,and the desulfurization rate reached 84%after 5 cycles of recycling.