Bi-Based Z-Scheme Nanomaterials for the Photocatalytic Degradation of Organic Dyes

A multicomponent Bi-based Z-scheme photocatalyst, BISB, was developed through a hydrothermal method. In this sample, two semiconducting nanostructures, BiOI and Bi₂S₃, were linked together with the metal Bi nanoparticle. As compared with BiOI (BI) and heterojunction BiOI/Bi₂S₃ (BIS) samples, the BISB had optimal Rhodamine B (RhB) photodecomposition performance. High efficiency separation of photoexcited electrons and holes, decreased band gap energy, extended specific surface area, and promotional redox potential were key factors for enhancing the photocatalytic activity of the prepared sample. The photoexcited holes were the key active radicals during the RhB photodecomposition process over the BISB catalyst, while ·O₂ was also involved to a smaller extent. Additionally, the photocatalyst demonstrated excellent reusability and stability during the photoreaction process, suggesting that the BISB sample could be a candidate for water purification applications.