Two-Phase Synthesis in n-Hexane–Water, Characterization, and Photocatalytic Activity of ZnO/Bi₂Sn₂O₇ Nanocomposite

The synthesis, characterization, and photocatalytic activity of ZnO/Bi₂Sn₂O₇ nanocomposite are reported herein. ZnO/Bi₂Sn₂O₇ was synthesized using a green high-speed stirring (HSS)-assisted method in the n-hexane–water system using Cassia alata leaf extract (CLE). ZnO/Bi₂Sn₂O₇ nanocomposite formed at the interface between n-hexane and water owing to the essential role of CLE secondary metabolites. Various analytical techniques were applied to characterize the optical, structural, and morphological properties as well as particle size of the nanocomposite. The ZnO/Bi₂Sn₂O₇ nanocomposite with average particle size of 9.8 nm exhibited efficiency of 86.59% for degradation of rhodamine B within 120 min. This high visible-light-driven photocatalytic activity was obtained by modification of ZnO with Bi₂Sn₂O₇, resulting in a decrease of the bandgap energy from 3.12 eV to 2.80 eV. This research offers a novel method for efficient synthesis of nanocomposites with high photocatalytic activity.