Hydrogen sulfide conversion: How to capture hydrogen and sulfur by photocatalysis

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 H₂ 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 H₂ 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.