Fabrication of Z-scheme Ag3PO4/TiO2 Heterostructures for Enhancing Visible Photocatalytic Activity

• Main Authors: Wenhui Liu, Dengdeng Liu, Kun Wang, Xiaodan Yang, Shuangqi Hu, Lishuang Hu
• Format: Article
• Language: English
• Published: SpringerOpen 2019-06-01
• Series: Nanoscale Research Letters
• Subjects: Composite; Heterostructures; Superoxide anion; Photocatalytic degradation
• Online Access: http://link.springer.com/article/10.1186/s11671-019-3041-8
• ISSN: 1931-7573; 1556-276X

Abstract In this paper, a synthetical study of the composite Ag3PO4/TiO2 photocatalyst, synthesized by simple two-step method, is carried out. Supplementary characterization tools such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and UV-vis diffuse reflectance spectroscopy were adopted in this research. The outcomes showed that highly crystalline and good morphology can be observed. In the experiment of photocatalytic performance, TiO2400/Ag3PO4 shows the best photocatalytic activity, and the photocatalytic degradation rate reached almost 100% after illuminating for 25 min. The reaction rate constant of TiO2400/Ag3PO4 is the largest, which is 0.02286 min−1, twice that of Ag3PO4 and 6.6 times that of the minimum value of TiO2400. The degradation effect of TiO2400/Ag3PO4 shows good stability after recycling the photocatalyst four times. Trapping experiments for the active catalytic species reveals that the main factors are holes (h+) and superoxide anions (O·− 2), while hydroxyl radical (·OH) plays partially degradation. On this basis, a Z-scheme reaction mechanism of Ag3PO4/TiO2 heterogeneous structure is put forward, and its degradation mechanism is expounded.