Research On The Preparation And Photocatalytic Activity Of CdS/Cd₂Ge₂O₆ And Bi₇O₉I₃/Zn₂SnO₄ Photocatalysts

With the development of industry, a growing number of dyes and chemical products, which are widely used, are difficult to fully biodegradable. Recently, photocatalytic technology has attracted researchers’ attention to pollutant degradation completely and high-efficiently at normal temperatures and pressures. Therefore, photocatalytic technology has been replacing traditional processing methods. Photocatalyst, centered with Ti O2, has been in the development and utilization. However, its practical application in photocatalysis is limited due to low quantum yield, low availability, easy deactivation and other defects. Thus, efficient photocatalyst has turned focus on none-Ti O2.Zn2Sn O4 and Cd2Ge2O6 possess broad band gap and special rod structure. So it has important significance to photocatalyst modification. According to plenty of literatures, Cd S/Cd2Ge2O6 and Bi7O9I3/Zn2 Sn O4 were prepared by hydrothermal, oil bath and other methods. Scanning electron microscopy(SEM), X ray diffraction(XRD), UV Vis diffuse reflectance spectroscopy(DRS), fluorescence spectroscopy(PL) and photocurrent(PC) were employed to characterize morphology, structure, optical absorption ability and light response range of photocatalyst. These efficient and stable photocatalysts were successfully synthesized. The main contents and results were as following:(1) Cd S/Cd2Ge2O6 visible light catalyst was synthesized by hydrothermal-oil bath. The catalytic performance of composite catalyst was much better than that of pure. In addition, the optimum mass ratio of Cd S/Cd2Ge2O6 was 10%. Methylene blue(MB) could degradate completely within 2 h. Cd S/Cd2Ge2O6 was in good with stability in repeated batch experiments, implied that it’s suitable to practical application. Catalytic mechanism was futher dicussed by capture agent and light current. The –OH played an important role in MB degradation under visible light.(2) Bi7O9I3/Zn2 Sn O4 visible light catalyst was synthesized by hydrothermal-oil bath. The catalytic performance of composite catalyst was much better than that of pure. In addition, the optimum mass ratio of Bi7O9I3/Zn2 Sn O4 was 1:2. Phenol could degradate completely within 4 h. Bi7O9I3/Zn2 Sn O4 was in good with stability in repeated batch experiments, implied that it’s suitable to practical application. Catalytic mechanism was futher dicussed by capture agent and light current. The O2- played an important role in MB degradation under visible light.The innovation points of this paper:(1) Cd S/Cd2Ge2O6 and Bi7O9I3/Zn2 Sn O4 visible light catalyst were first synthesed. Moreover, two materials are heterojunction photocatalyst;(2) Cd S/Cd2Ge2O6 and Bi7O9I3/Zn2 Sn O4 exhibited efficient and stable photocatalytic performance, which was conducive to practical application;(3) Cd S/Cd2Ge2O6 and Bi7O9I3/Zn2 Sn O4 were both modifidied semiconductor without visible light activity. The obtained results could provide more information for none-Ti O2 visible light heterojunction catalysts.