Construction of novel amphiphilic [Bmin]3PMo12O40/g-C3N4 heterojunction catalyst with outstanding photocatalytic oxidative desulfurization performance under visible light

Oxidative desulfurization technology has attracted the attention of many catalytic scholars because of its high desulfurization efficiency and mild conditions. However, during the catalytic reaction, the oxidant and the sulfur-containing compounds are separated into two phases, and the mass transfer problem becomes the biggest obstacle to suppress the desulfurization effect. In this work, a novel amphiphilic material [Bmin]3PMo12O40 (BPMO) was prepared and loaded onto porous g-C3N4 with a 2D structure using an in situ precipitation method. Using hydrogen peroxide as the oxidant and dibenzothiophene (DBT) n-heptane solution as the simulated oil, the photocatalytic oxidative desulfurization properties of the catalyst under visible light were investigated. The results show that the BPMO can simultaneously adsorb DBT in the oil phase and H2O2 in the water phase during the reaction and promote the mass transfer at the oil–water interface. g-C3N4 not only increases the dispersion of BPMO as a carrier, but forms a heterojunction with BPMO and effectively increases the utilization rate of electrons. Thus, BPMO/g-C3N4 can efficiently oxidize simulated oil with a sulfur content of 1000 ppm while showing excellent catalytic stability. The possible mechanism of the photocatalytic oxidative desulfurization process is discussed.