A cost-effective H2S pollutant electro-transformation to hydrogen clean fuel and value-added semiconducting materials: A green alternative to Claus process

A straightforward strategy to resolve the H2S problem is its neutralization in alkaline media, followed by electrolysis of the obtained solution upon suitable electrodes. Herein, we report for the first time that via galvanostatic electrolysis of the resulting alkaline sulfide medium over copper electrodes, this harmful pollutant could be safely as well as cost-effectively transformed to hydrogen clean fuel and a valueadded eco-friendly semiconducting material. The strong interaction of copper with bisulfide (the dominant species of the medium at pH 11) resulted in a significant decrease in the system impedance, accompanied by less electricity consumption during the process. A nano/micro-structured, mesoporous morphology was observed for the anodic product (surface area: 11.4 m2/g). Photoelectrochemical and diffuse reflectance as well as XRD, EDX, XPS and photoluminescence investigations revealed that the material synthesized upon the anode surface was a narrow bandgap (Eg = 1:63eV) p-type semiconductor. In addition to the economic perspective of the proposed electrolysis process (3 - 6 USD/kgH2), the underlying mechanism of simultaneous production of semiconductor (CuS) and H2 was thoroughly discussed. CO 2023 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.