Visible-light induced photocatalytic oxidative desulfurization using BiVO4/C3N4@SiO2 with air/cumene hydroperoxide under ambient conditions

Trace amount of thiophenic compounds in fuel is harmful to the environment and challenging to get rid of efficiently. The objective of this work is to explore a new visible-light induced photocatalytic oxidative desulfurization (PODS) approach using BiVO4/C3N4@SiO2 with air/cumene hydroperoxide (CHP) under ambient conditions. A series of BiVO4/C3N4@SiO2 photocatalysts were prepared by a hydrothermal method and PODS tests were carried out in a Xenon lamp built-in batch reactor. The dibenzothiophene conversion of the PODS system reached as high as 99%. BiVO4/C3N4@SiO2 showed high vis-photocatalytic activity due to the effective charge separation of BiVO4/C3N4 and small particle size of BiVO4. Additional air flow was demonstrated to effectively enhance PODS kinetics of BiVO4/C3N4@SiO2 with CHP, which may be ascribed to the accelerated ROO generation by air with R radical for DBT oxidation. Mixing silica gel with BiVO4/C3N4@SiO2 as a hybrid adsorbent under photocatalytic adsorptive desulfurization (PADS) showed a dramatically enhanced desulfurization capacity (7.2 mg/g) compared to that under sole ADS. When fitted to Langmuir adsorption isotherm, K and qm reached as high as 0.24 and 7.41. The integrated PADS system can be particularly suitable for s single-stage desulfurization for low-sulfur fuel production under visible light at ambient conditions.