Photocatalytic oxidation desulfurization is presently challenged with low quantum efficiency and high combination rate of electron–hole, and the key to success is to design efficient multicomponent composite photocatalysts. This work successfully synthesized Z-scheme photocatalysts ZnM-LDHs/g-C3N4 (M = Al, Cr) by the electrostatic self-assembly, analyzed their work mechanism through various characterization technique such as XPS, PL, TRPL, and ESR, explored the activity enhanced mechanism, and revealed the reason of their catalytic activity difference. Photocatalytic oxidation/extraction desulfurization of ZnAl-LDHs/g-C3N4 and ZnCr-LDHs/g-C3N4 can achieve 99.8 and 96.6%, respectively, in 3 h for model oil. The results are instructive for the structure design and study of efficient photocatalysts in desulfurization.

High-carbon alkyl dibenzothiophenes (DBTs) in real diesel are difficult to remove. Their steric effect has been studied and identified as the controlling factor in heterogeneous catalytic oxidation desulfurization (ODS) process. Mixed alkyl DBTs (C 2 -DBT, C 2 -C 2 -DBT, C 3 -DBT, and C 3 -C 3 -DBT) were synthesized via DBT's Friedel-Crafts alkylation, and their reactivity is DBTC 2 -C 2 -DBT, and C 3 -C 3 -DBT can be hardly removed by any of three efficient heterogeneous ODS processes, but are removed efficiently in a homogeneous ODS process of HAc-HPW-H 2 O 2 , which contrasts the great importance of their steric effects in heterogeneous catalytic process. Thus, the frustrating efficacy of various ODS processes for real diesel is likely originated from the unidentified high-carbon alkyl DBTs and their least reactivity in heterogeneous catalytic systems. And, the steric hindrance is diminished greatly in a homogeneous catalytic process. The results are instructive for the development of new catalysts and catalytic ODS processes for real diesel.