Facile one-step synthesis of a novel Bi2S3/BiOCl0.1Br0.9 S-scheme heterojunction photocatalyst with enhanced photocatalytic performance: function of interfacial electric field

Abstract

Based on the anion exchange strategy, a novel Bi₂S₃/BiOCl_0.1Br_0.9 S-scheme heterojunction was prepared via a facile one-step low-temperature water bath method for the first time. In this process, 2D Bi₂S₃ nanosheets were controllably grown on the surface of a 3D hollow BiOCl_0.1Br_0.9 solid solution. Under visible light irradiation, the as-prepared 3BS-BCB exhibited a remarkable photocatalytic degradation efficiency of 99.67% toward rhodamine B (Rh B) within 140 min, which is approximately 3.57 times higher than that of the BiOCl_0.1Br_0.9 solid solution alone. The enhanced photocatalytic performance is attributed to the formation of an interfacial electric field (IEF), which accelerated the separation rate of photoinduced electron–hole pairs and coupled the strong redox ability of both the semiconductors. Moreover, the photosensitive effect of Bi₂S₃ extended its light absorption range, increasing the yield of photogenerated charge carriers. Such thermodynamic and kinetic compatibility is the fundamental reason for the enhanced photocatalytic efficiency. This study provides new insights into the design of S-scheme heterojunction photocatalysts with visible light response and high redox ability based on wide-band gap semiconductors.