Poly(vinyl pyrrolidone)-assisted hydrothermal synthesis and enhanced visible-light photocatalytic performance of oxygen-rich bismuth oxychlorides

A series of novel oxygen-rich bismuth oxychloride (Bi12O17Cl2) were synthesized through a facile poly (vinyl pyrrolidone) (PVP)-assisted hydrothermal route. These obtained Bi12O17Cl2 samples were characterized by various physicochemical techniques. It was found that a proper addition amount of PVP could promote the transformation of Bi12O17Cl2 morphology from irregular clusters to three-dimensional hierarchical flower-like microspheres that were nominated as sample BP2. As-synthesized samples were subjected to a photocatalytic degradation of dye Rhodamine B (RhB) or 2,4-dichlorophenol (2,4-DCP) under visible light. Among all candidates, the sample BP2 with a hierarchical flower-like morphology showed the best degradation efficiency for RhB and 2,4-DCP. The apparent rate constant of sample BP2 in terms of degradation of RhB was nearly 5.7 and 45 times that of unmodified BP0 and N-TiO2. The enhanced photocatalytic performance could be ascribed to synergetic effects including unique hierarchical morphologies, large specific surface area, small particle size, good crystallinity, and suitable band structures. A possible mechanism of catalytic degradation was finally proposed basing upon the active species trapping experiments. (C) 2015 Elsevier Inc. All rights reserved.