Hydrogen sulfide conversion: How to capture hydrogen and sulfur byphotocatalysis

H2S is a notorious gas widely generated in the petrochemical industry. How to handle H2S effectively and convert it into highly-valued products is vital. Photocatalysis is promising in this field, as it could directly utilize solar light and convert H2S into H-2 and S. In this review, the properties of hydrogen sulfide (H2S) is overviewed first, and conventional techniques (Claus process, thermolysis, non-thermal plasma, electrochemistry and other methods) for H2S conversion are simply introduced. Basic knowledge of photocatalysis and general strategies for enhancing the activities of photocatalysts are presented as well. Then typical work for photocatalytic conversion of H2S in gas phase and liquid phase are introduced case by case, with the generated H-2 as the main product in these systems. Furthermore, methods for extraction of elemental sulfur from H2S by photocatalysis-related methods were discussed, with specific attention on photoelectrochemical cells and photovoltaic-electrochemical cells. In the end, current status of the research on photocatalytic conversion of H2S is summarized, and challenges in this field is put forward. In addition, some other possible strategies for photocatalytic conversion of H2S into highly-valued chemicals instead of hydrogen and elemental sulfur will be discussed, which is aimed to inspire researchers interested in this field. (C) 2019 Elsevier B.V. All rights reserved.