Complete mineralization of a humic acid by SO4 ·- generated on CoMoO4/gC3N4 under visible-light irradiation.

ABSTRACT

The sulfate radical ([Formula see text]), almost a most active species, is believed to be the best oxidant in the elimination of aquatic organics in advanced oxidation processes. However, acquiring their steady-state generation with high concentration is still challenging work. In this report, we focused on designing a novel composite, in which uniform and rod-like CoMoO4 was fabricated on gC3N4 through Co-N coordination. In this way, the composite acquired an immobilization of Co (II) in its refraining from leaking, and synchronically, a dense heterojunction between CoMoO4 and gC3N4. Over the heterojunctions, photogenerated electrons gained a prolonged lifetime through their efficient separation from holes. The life-prolonged electrons, together with Co (II) in CoMoO4, effectively activated the persulfate, and a concentration of steady-state [Formula see text] as high as 1.8 × 10-14 mol · l-1 was obtained. With [Formula see text] fast and complete mineralization of a humic acid was achieved.