Enhanced photocatalytic degradation activity via a stable perovskite-type LaFeO3/In2S3 Z-scheme heterostructured photocatalyst: Unobstructed photoexcited charge behavior of Z-scheme photocatalytic system exploration

Materials of perovskite-type structure have been widely investigated for their prospect in photocatalysis. In this work, a novel composite material of p-type LaFeO3 microsphere coated with n-type In2S3 nanoparticles was fabricated to settle the water pollution problems through a mild hydrothermal method. The structure and morphology were studied by XRD, SEM, TEM, EDX mapping and UV-visible absorption spectra. The results indicated that the LaFeO3/In2S3 heterostructured photocatalyst was prepared successfully, and show an enhanced BET surface area and visible light absorption. The obtained heterostructured photocatalyst was applied to the photocatalytic degradation of rhodamine B (Rh B), tetracycline (TCH) and brilliant blue (BB). Under optimized conditions, the degradation rate of LaFeO3/In2S3 photocatalyst was dozens of times that of the pristine LaFeO3 and pristine In2S3. Notably, the degradation rate constant for Rh B, TCH and BB was 0.16709, 0.02684 and 0.0175 min(-1) over as-prepared LaFeO3/In2S3 photocatalyst, respectively. The surface photovoltage (SPV), reactive oxidation species scavenger (ROSs) and work function (WF) tests were applied to investigate the photoexcited charge behavior of LaFeO3/In2S3 and the possible mechanism of photocatalytic degradation. The results demonstrate that the band bending is formed at the LaFeO3/In2S3 heterostructured interface because the WF of LaFeO3 is higher that of In2S3, which leads to the transfer of photoexcited electron from conduction band (CB) of LaFeO3 to valence band (VB) of In2S3 and the excellent photocatalytic degradation activity of water pollutants. And the Z-scheme charge transfer process was suggested at the LaFeO3/In2S3 interface based on the energy band structure of LaFeO3 and In2S3 and ROSs results. Therefore, we believe that our rationally conceived LaFeO3/In2S3 heterostructured photocatalyst advances the development of photocatalytic degradation and environmental remediation. (C) 2022 Elsevier B.V. All rights reserved.