Modulation of the excited-electron recombination process by introduce g-C3N4 on Bi-based bimetallic oxides photocatalyst

• DOI: 10.1016/j.apsusc.2017.06.156
• Publication Date: 2017-06-20T21:00:37Z
• Authors: Duanduan Liu; Zhiliang Jin; Hongxuan Li; Gongxuan Lu
• Keywords: Graphitic carbon nitride; Bimetallic strip; Carbon nitride; Photocurrent

Abstract The Bi-based bimetallic oxides photocatalyst Bi7.53Co0.47O11.92 was successfully synthesized and the graphite phase carbon nitride (g-C3N4) was loaded, and a novel composite photocatalyst Bi7.53Co0.47O11.92/g-C3N4 was obtained as well. The photocatalyst Bi7.53Co0.47O11.92, possessed tetragonal crystal structure, with the introduction of g-C3N4, the H2 production reached the maximum about 108 μmol under continuous visible light irradiation for 4 h, which was 13 times higher than that of pure g-C3N4 photocatalyst. A series of studies shown that the g-C3N4 on the surface of Bi7.53Co0.47O11.92 provided the more active sites and improved the efficiency of photo-generated charge separation by means of several characterizations such as SEM, XRD, XPS, element mapping, UV–vis DRS and FTIR. etc. and the results of which were in good agreement with each other. The composite photocatalyst Bi7.53Co0.47O11.92 has a greater specific surface area and pore volume compared to pure g-C3N4, which is more favorable for the adsorption of dye molecules, leading to enhance the composite photocatalytic activity consequently. The excited-electron recombination process was greatly modulated with the introduce g-C3N4 on the surface of Bi-based bimetallic oxides photocatalyst and the photostability was enhanced as well. The promoted charge separation was measured by means of the EIS, photocurrent and transient fluorescence. In addition, a possible reaction mechanism over eosin Y-sensitized Bi7.53Co0.47O11.92/g-C3N4 photocatalyst under visible light irradiation was proposed.