One-Pot Strategy to Bi₂S₃/BiOCl Heterojunction with Enhanced Photocatalytic Activity

Bi₂S₃/BiOCl (denoted as BS-BC) heterojunction photocatalyst has been reported to be able to increase light absorption, promote charge separation and consequently enhance photocatalytic efficiency in comparison with single BiOCl. However, the heterojunction was usually prepared by a two-step method, i.e., BiOCl was firstly prepared and then to BS-BC heterojunction through an ion exchange strategy. In this work, BS-BC was prepared by a one-pot room temperature route, where Bi(NO₃)₃ dissolved in aqueous urea solution could homogeneously react with a mixture solution of NaCl and thiacetamide (TAA) to form BS-BC heterojunction. The urea could prohibit the hydrolysis of Bi(NO₃)₃ and accelerate the decomposition of TAA to release S²⁻, and as a consequence, the heterojunction photocatalyst with small size and large interfacial area could be prepared in several hours. The resulted heterojunction exhibited better visible-light photocatalytic activity for RhB degradation than individual BiOCl or that prepared by a two-step route due to close contact between Bi₂S₃ and BiOCl, modified band structures and effective interfacial charge transfer.