A CuS/Fe2TiO5 Heterojunction Photocatalyst for Highly Efficient Photocatalytic Degradation of Rhodamine B

Abstract

Constructing heterojunctions is important for improving the photocatalytic performance of materials. In this study, porous Fe₂TiO₅ was prepared via a sol-gel method, and CuS was grown in situ on its surface through a hydrothermal process, thereby successfully synthesizing CuS/Fe₂TiO₅ heterojunction composites. The CuS/Fe₂TiO₅ composites were characterized via X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (UV-Vis), and Brunauer–Emmett–Teller (BET) analysis. The results indicated that CuS is uniformly loaded on the surface of Fe₂TiO₅, with lattice spacings of 0.3550 and 0.2972 nm corresponding to CuS and Fe₂TiO₅, respectively, and no impurity phases were observed. Heterojunction construction induced distortion of the TiO₆ octahedra at the interface, resulting in the emergence of a new absorption peak in the ultraviolet region. Among the samples, the 20 wt.% CuS/Fe₂TiO₅ (denoted as 20CuF₂) composite exhibited a specific surface area (S_BET = 6.17 m²/g) between those of CuS (S_BET = 4.87 m²/g) and Fe₂TiO₅ (S_BET = 7.71 m²/g). Its bandgap was tuned to 1.78 eV, and the photoluminescence intensity was significantly reduced. A CuS/Fe₂TiO₅ heterojunction composite was applied to facilitate the degradation of rhodamine B (RhB), achieving a degradation efficiency of 91.8%. The heterojunction catalysts developed in this study enable the effective degradation of pollutants in wastewater, providing a feasible technical reference for catalyst development and application.