Preparation And Photocatalytic Properties Of Bi₂S₃/BiFeO₃ Composite Photocatalyst

With the development of chemical industry,a large number of organic pollutants which can not be treated effectively polluted water environment seriously.Therefore,it is a major problem in the modern society to find a new,efficient,clean and environmentally friendly method to adress the problem of water pollution.Photocatalytic method is widely concerned by researchers,which has the advantages of low energy consumption,mild conditions,applicable range and less secondary pollution.BiFeO3,a typical rhombohedral phase semiconductor with a narrow band gap?2.2 eV?and large absorption coefficient,has received the widespread attention.The research contents are as follows:1.In this paper,Bi₂S₃-sensitized Bi FO3?BFO?photocatalyst?Bi₂S₃/BFO?was successfully synthesized hrough a facile and environmental ion exchange method that combined two steps processes of sol gel method and solvothermal method.The crystalline phase and morphology of as-prepared photocatalysts were characterized using X-ray diffraction?XRD?,scanning electron microscopy?SEM?,energy-dispersive X-ray spectroscopy?EDS?,and UV-vis diffuse reflection spectroscopy?DRS?.Bi₂S₃/BFO composite materials were failed to prepare by a hydrothermal process using deioned water as solvent,however,it was successfully fabricated through a solvothermal route using absolute alcohol as solvent.Furthermore,the best preparation conditions were determined.The results obtained by photocatalytic degradation experiment of Rh B dye solution showed that Bi₂S₃/BFO composite photocatalyst with heterogeneous structure exhibited good dispersion and excellent photocatalytic performance when the reaction temperature was 180 ?,the reaction time was 6h and the theoretical molar percentage of TU to initial BFO was 5%.2.The optimum conditions of 5% Bi₂S₃/BFO composite photocatalyst treating RhB dye aqueous were obtained by single factor experiment and orthogonal experiment: Initial dye solution pH was 3,composite photocatalyst dosage was 1 g/L,initial dye solution concentration was 10 mg/L;after the reaction under visible light irradiation 180 min,the decoleration rate and COD removal rate of Rh B were 96% and 78.21%,respectively.3.Study on the kinetics of treated Rh B dye wastewater by Bi₂S₃/BFO composite catalyst.The photocatalytic reaction kinetics of photocatalytic degradation of Rh B was in accordance with the first order kinetics model:C_t=C₀exp(1.0904C₀^-1.8489Q^-0.6949P^-0.2742t)...