Bifunctional photoelectrochemical sensor based on Bi/Bi2S3/BiVO4 for detecting hexavalent chromium and hydrogen peroxide

Abstract

In this study, a bifunctional photoelectrochemical (PEC) sensor based on Bi/Bi2S3/BiVO4 (Bi-BSV) is prepared by one-step hydrothermal method. Firstly, the results from experiments show that the PEC performances of Bi2S3/BiVO4-X (BSV-X, X = m(Bi2S3)/m(Bi2S3 + BiVO4)) are higher than those of Bi2S3 and BiVO4, and BSV-15% has the highest PEC performance. To further improve the PEC properties of BSV-15%, metal-Bi was introduced to the synthesis of Y-Bi-BSV-15% (Y represents the amount of glucose added). Moreover, UV–visible diffuse reflectance spectrum (UV–vis DRS) and photoluminescence (PL) demonstrate that 0.3-Bi-BSV-15% has the widest visible light absorption range and strongest photogenerated carriers separation capability among all composites. Based on the above results, the PEC sensor based on the 0.3-Bi-BSV-15% for detecting hexavalent chromium (Cr (VI)) and hydrogen peroxide (H2O2) is built. The results exhibit that 0.3-Bi-BSV-15% has a wider detection range of 2–230 µM and a lower detection limit of 0.094 µM for Cr (VI) detection. While for H2O2 detection, the detection range and detection limit are 1–130,000 µM and 0.089 µM, respectively. Therefore, 0.3-Bi-BSV-15% has potential application in Cr (VI) and H2O2 detection.