Mo2C/C catalyst as efficient peroxymonosulfate activator for carbamazepine degradation

Compared with generally reported Mo 4+ /Mo 6+ redox cycle, the exposed Mo 2+ active sites of Mo-based materials may have a superior potential to effectively activate PMS. However, Mo 2+ -involved materials as efficient catalysts in sulfate radical-based advanced oxidation processes (SR-AOPs) has rarely been researched. In this work, a spherical Mo 2 C-loaded carbon material, Mo 2 C/C, was prepared for the first time by hydrothermal-calcination method directly used as peroxymonosulfate (PMS) activator towards carbamazepine (CBZ) degradation. The results showed that the Mo 2 C/C could effectively remove nearly 100% CBZ (5 mg·L −1 ) in the presence of 0.75 mM PMS within 75 min under the optimal conditions. It was attributed to the reductive Mo 2+ , as active sites, benefits to absorb PMS on the surface to trigger electron transmission, and the defective carbon structures accelerate the activation of PMS. Consequently, the efficient Mo 2+ /Mo 4+ /Mo 6+ electron transfer was achieved, resulting in excellent catalysis. A series of reactive species including SO 4 − , OH and 1 O 2 species participated in CBZ oxidation degradation. Derived from the superior stability and reusability of Mo 2 C/C, the removal rate of CBZ still maintained above 80% even after five consecutive cycles, which is expected to be applied in the wastewater treatment including pharmaceuticals in the future. • A novel spherical Mo 2 C-loaded carbon material was synthesized. • Mo 2+ active sites in Mo 2 C/C for efficient PMS activation. • Mo 2+ /Mo 4+ /Mo 6+ electron transfer triggered the formation of SO 4 − , OH and 1 O 2 . • Efficient removal of carbamazepine in Mo 2 C/C/PMS system was achieved.