Oxidative desulfurization of dibenzothiophene and simultaneous adsorption of products on BiOBr-C3N4/MCM-41 visible-light-driven core-shell nano photocatalyst

In this study, different amounts of BiOBr (x = 0, 5, 10, 15 wt%) and 5% wt. of g-C3N4 were loaded on MCM-41 as core for photo oxidation of DBT and simultaneous adsorption of oxidation products. Among studied photocatalysts, the BiOBr-C3N4/MCM-41 photocatalyst with 10% wt. of BiOBr indicated the highest activity so that this sample reduced DBT concentration to the lowest value of C/C0 = 0.08 after 150 min irradiation of visible light. The characterization of the as prepared photocatalysts by XRD, FESEM, TEM, FTIR, BET-BJH, UV-Vis DRS, and PL analyses revealed that this achievement was due to the highest amount of structural defects and the strongest interaction between BiOBr-C3N4 shell and MCM-41 core in this sample. Moreover, this sample indicated the lowest recombination rate of charge carriers, the narrowest band gap, and high porosity that enhanced the photocatalytic efficiency. However, this sample lost 18% of initial activity after four successive cycles of photo oxidation-adsorption that based on FTIR and BET-BJH was because of plugging of pores by DBT sulfones.

Automated summary

Different amounts of BiOBr and g-C3N4 were loaded on MCM-41 to achieve efficient photo oxidation and adsorption of DBT. The optimal photocatalyst, BiOBr-C3N4/MCM-41 with 10% BiOBr, showed highest activity and lowest DBT concentration, attributed to the highest structural defects and strongest interaction. However, after four cycles, a decrease in activity was observed due to pores blockage by DBT sulfones.