Multi-active photocatalysts of biochar-doped g-C3N4 incorporated with polyoxometalates for the high-efficient degradation of sulfamethoxazole

Sulfamethoxazole (SMX) is one of major antibiotic contaminants in current aqueous environment. In this paper, waste loofah and melamine were co-carbonized to prepare biochar-doped g-C 3 N 4 (CCN) by a one-pot method and then combined with Co 2 PMo 11 VO 40 (CoPMoV) using a binder to obtain the novel polyoxometalates (POMs) photocatalytic composites (CCN/CoPMoV). The incorporation of CoPMoV dramatically reduced the photogenerated carrier recombination and led to a small band gap. Under visible light, the synergetic activation from biochar, g-C 3 N 4 and POMs can remove 98.5% of SMX ( k  = 0.215 min −1 ) in the peroxymonosulfate (PMS) system within 20 min and keep its high stability with the degradation of 88.9% after five cycles. Multi-active sites from CCN/CoPMoV are contributed to develop the most active species of SO 4 − ∙ , ·OH, 1 O 2 , and h + . The validity in the degradation of SMX makes CCN/CoPMoV a promising and potential material for the removal of aqueous pollutants in the future.