Desulfurization through Photocatalytic Oxidation: A Critical Review

Abstract

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 .O2− 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.

A current overview of the oxidative desulfurization of fuels utilizing heat and solar light: from materials design to catalysis for clean energy

“…26 In the work of Zhou and co-workers, the salient challenges in photocatalytic ODS, including rapid charge carrier recombination rate and deficient light absorption capability, along with the countermeasures were reported to guide the future development of photocatalytic ODS. 27 The catalytic performances of various homogeneous and heterogeneous ODS catalysts have also been critically discussed and compared in several reports. [28][29][30] The applications of ionic liquids (ILs), [31][32][33] polyoxometalates (POMs), 34 metalorganic frameworks (MOFs) 35,36 and graphene 11 in ODS have also been individually reviewed.…”

“…46,47 The adsorbed DBT and H 2 O molecules readily react with a hole in the VB and form reactive intermediates composed of a radical cation and hydroxyl radicals ( OH), respectively, through the oxidation process (3). 27 Meanwhile, O 2 undergoes a reduction process in the CB (3) and transforms into energetic oxygen species including superoxide radicals ( O 2 À ) and OH radicals (3). [48][49][50][51][52] Consequently, the redox reaction is accomplished, followed by the desorption of the products from the surface of the photocatalyst.…”

Photocatalytic Air Purification Using Functional Polymeric Carbon Nitrides

“…The emission of sulfur compounds accelerates the erosion of the historical building, destroys soil chemistry, and disturbs the pH of water bodies, thereby jeopardizing marine life. [10][11][12]269] Moreover, breathing in a toxic climate can result in numerous health concerns (e.g., asthma, heart disease, and respiratory syndrome). [11,[270][271][272] Notably, the source of sulfur com- [12] Copyright 2021, Wiley-VCH.…”

“…[ 1 , 2 , 3 , 4 , 5 ] The undesirable and harmful materials of air pollutants (e.g., nitrogen oxides (NO x ), sulfur compounds, volatile organic compounds (VOC), and other species (carbon monoxide) enter the atmosphere from sources currently beyond human control. [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ] These man‐made air pollutants are primarily produced from counts of life and industry (e.g., transportation, fossil fuel combustion, vehicle exhaust, industrially processes, and miscellaneous). [ 2 , 21 , 22 , 23 ] The quantities effects generated from the harmful air pollutants may seriously damage the global environment, which may induce acid rain, thereby destructing the ozone layer by chlorofluorocarbons; and deteriorate the human/animal health, thereby causing respiratory problems; and increase the form of brown or hazy air or unpleasant smells.…”

Heterostructure of vanadium pentoxide and mesoporous SBA-15 derived from natural halloysite for highly efficient photocatalytic oxidative desulphurisation

“…Besides physical and biological methods, photocatalytic oxidative desulphurisation has gained signicant attention due to its economic and green merits and high efficiency. [3][4][5][6] This technology can convert sulphurcontaining compounds into sulfone groups using abundant solar irradiation at ambient temperature, reducing costs and energy consumption to a reasonable level. Since the rst photocatalytic oxidative desulphurisation of dibenzothiophene (DBT) in acetonitrile using TiO 2 was reported in 2002, 7 signicant improvements have been made to photocatalytic efficiency.…”