Preparation of SrTiO₃/Bi₂S₃ Heterojunction for Efficient Photocatalytic Hydrogen Production

Abstract

SrTiO3, Bi2S3, and SrTiO3/Bi2S3 heterojunction were prepared for efficient photocatalytic hydrogen production. SrTiO3/Bi2S3 heterojunction was prepared by different weight percentages of Bi2S3 (1, 3, 5, and 7%) with SrTiO3. SrTiO3 and Bi2S3 are exhibited in cubic and orthorhombic crystal structures, respectively. The morphologies of SrTiO3 and Bi2S3 have existed as nanocubic and bar-like structures, respectively. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) results further confirmed the formation of SrTiO3/Bi2S3 heterojunction. The photoluminescence (PL) and electrochemical impedance spectroscopy (EIS) results indicated that the SrTiO3/Bi2S3 heterojunction reduces the rate of photogenerated electron–hole pair recombination and electron-transfer resistance than pure SrTiO3 and Bi2S3. The formation of SrTiO3/Bi2S3 heterojunction effectively separates the photogenerated charge carriers, which enhances the photocatalytic hydrogen production under UV light. The SrTiO3/Bi2S3 heterojunction shows superior photocatalytic hydrogen production than bare SrTiO3 and Bi2S3 due to the synergistic effect. The photocatalytic hydrogen production of SrTiO3/Bi2S3 (5%) gives 7.7 mmol g–1 within 180 min under UV irradiation.