An efficient mass transfer process is a critical factor for regulating catalytic activity in a photocatalytic desulfurization system. Herein

a phosphotungstic acid (HPW) active center is successfully composited with a quaternary ammonium phosphotungstate-based hexadecyltrimethylammonium chloride ionic liquid (CTAC-HPW) by the ion exchange method for the photocatalytic oxidative desulfurization of dibenzothiophene sulfide. The keggin structure of HPW and highly mass transfer performance of organic cations synergistically enhanced the photocatalytic activity towards the effective convertion of dibenzothiophene (DBT) with the excitation of visible light. The deep desulfurization (10 mg·kg

-1

) is attained within 30 min

and well stability is demonstrated within 25 cycles. Moreover

the CTAC-HPW photocatalyst projects well selectivity to interference from coexisting compounds such as olefins and aromatic hydrocarbons and universality of dibenzothiophenes

for example

4-methyldibenzothiophene (4-MDBT) and 4

6-dimethyldibenzothiophene (4

6-DMDBT). Ultimately

a possible photocatalytic desulfurization mechanism is proposed according to the Gaschromatography-mass spectrometry (GC-MS)

proving that the final product is the corresponding sulfone. The trapping experiment and electron spin resonance (ESR) analysis confirmed that h

+

and ·COOH played critical roles in the oxidation process. The work offers a practicable strategy for efficiently converting DBT

to DBTO

2

with added value.