Enhancement of ZnO catalytic activity under visible light by co-doping with Ga and Ti for efficient decomposition of methylene blue

作者：Luo, Qiuzi; Sun, Yihua^*; Guo, Jin; Zhang, Jiangyu; Fang, Liang

来源：Reaction Kinetics Mechanisms and Catalysis, 2022, 135(4): 2231-2246.

DOI：10.1007/s11144-022-02239-1

• ZnO
• Nanoparticles
• Sol-gel
• Co-doping
• Photocatalytic

The properties of ZnO nanoparticles doped with titanium ions (Ti4+) and gallium ions (Ga3+) were modified by sol-gel method. Considering the ion radius of doped metal elements, the radius of Zn ions and the doping limit of ZnO, the doping rate of Ti is fixed at 1 atom%, and the optimal doping amount of Ga is discussed. The Ga/Ti co-doped ZnO nanoparticles were characterized by X-ray diffraction (XRD), ultraviolet/visible spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and infrared spectroscopy. XRD results show that Ga/Ti co-doped ZnO has hexagonal wurtzite phase structure. With the increase of Ga doping concentration, the particle size of ZnO decreases. Through photoluminescence analysis, it is found that the absorption of Ga/Ti co-doped ZnO in the visible region moves to the long wave direction. In addition, with the increase of Ga doping, the particle size of GTZ powder first decreases and then increases, the band gap also decreases and then increases. When the doping amount of Ga is 1.5 atom%, the photocatalytic activity is the best. The degradation rate of MB was 90% within 2.5 h. Ga/Ti co-doped ZnO nanoparticles have good photocatalytic properties and low cost. They are a promising catalyst for wastewater treatment.