In this study, Bi2.15WO6 with different morphologies was successfully synthesized and used for the selective photooxidation of benzyl alcohol to benzaldehyde in aqueous solutions. High conversion (85%) and selectivity (85%) can be simultaneously achieved under alkaline conditions by adding ethylenediamine to protect the produced benzaldehyde from overoxidation. In the oxidation process, Bi–OO• and Bi–OOH on Bi2.15WO6, instead of OH• and O2 •–, are the primary oxidizing species to sequentially abstract two H (H+ + e–) from benzyl alcohol, accompanied by the formation of H2O2. Meanwhile, h+ and OH– also minorly contribute to the selective oxidation of benzyl alcohol via the H-abstraction pathway. This study enriches our understanding of the oxidizing species involved in the selective photooxidation of benzyl alcohol to benzaldehyde.

Turning aromatic sulfur impurities to value-added polymers is a promising technology for fuel desulfurization. In this study, Cu(I,II)@g-C 3 N 4 plates prepared via facile calcination show high reactivity in catalytic oxidation of benzothiophene (BT) by persulfate in a mixture of MeCN/H 2 O (v/v = 50/50). Quenching experiments rule out the primary contributions of SO 4•− , • OH, and O 2•− to BT oxidation and confirm the presence of carbon-centered radicals during the desulfurization process. XPS and Raman analyses reveal that Cu(I) and graphitic-N are reactive sites for persulfate activation, accompanied with moderate activation of the peroxo group in persulfate via the nonradical pathway. Solid characterizations indicate the formation of polybenzothiophene S,S-dioxide during the oxidation process, which further reveals that the moderately activated persulfate abstracts H from BT to form a BT radical cation, followed by subsequent polymerization of BT radical cations to a BT tetramer, and then the BT tetramer is further oxidized to a BT S,S-dioxide tetramer. The high electrochemical stability and pseudo-capacitive properties of the obtained polymers also imply their high potential to be used for capacitors. This work provides new insight on turning aromatic sulfur impurities in fuels to "treasures".

Selective oxidation of cyclohexane to cyclohexanol/ cyclohexanone (KA−oil) is an important chemical process, which is still constrained by low conversion and selectivity and high energy consumption. In this study, Cu-doped mesoporous TiO 2 (Cu-MT) has been successfully synthesized via calcinating MIL-125(Ti) doped with copper acetylacetonate, which shows high reactivity in selective oxidation of cyclohexane to KA−oil by persulfate (PS) with the desirable cyclohexane conversion of 16.8% and a selectivity of 98.0% under mild conditions and the low ratio of PS/cyclohexane of 1:1. A series of characterizations and density functional theory calculations reveal that the doped Cu(I,II) on Cu-MT is the reactive site for non-radical activation of PS with the moderate elongation of the O−O bond in PS, which then abstracts 1H (1H + + 1e − ) from cyclohexane to form Cy • and eventually KA−oil. This study gives new insight on the importance of moderately activated PS in selective oxidation of C−H.

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