Desulfurization through Photocatalytic Oxidation: A Critical Review.

Fuel oil, the most important strategic resource, has been widely used in industrial applications. However, the sulfur-containing compounds in fuel oil also present humanity with huge environmental issues and health concerns due to the hazardous combustion waste. To address this problem, the low vulcanization of fuel production technology has been intensively explored. Compared with traditional hydrodesulfurization technology, the newly emerged photocatalytic desulfurization has the advantages of milder operating conditions, lower energy consumption, and higher efficiency, holding great prospect to achieve deep desulfurization. Though great efforts have been made, the desulfurization catalysts still suffer from inferior light absorption, fast recombination of photocarriers, and poor structure modification. This Review summarizes recent development of photocatalytic desulfurization, including the desulfurization principle, current desulfurization challenges, and corresponding solutions. Particularly, the roles of defect engineering, hybrid coupling, and structure modifications in the enhancement of photocatalytic performance are emphasized. In addition, the photocatalytic desulfurization mechanism is also introduced with the OH and O radicals as main active species. Finally, some perspectives on the photocatalytic desulfurization are provided, which can further optimize the desulfurization efficiency and guide future photocatalyst design.