Improved photocatalyst: Elimination of triazine herbicides by novel phosphorus and boron co-doping graphite carbon nitride

A non-metallic and low-cost novel phosphorus and boron co-doping graphite carbon nitride (PB-g-C3N4) photocatalyst was prepared by a facile thermal copolymerization of urea with B2O3 and (NH4)2·HPO4. The novel PB-g-C3N4 exhibited excellent optical and electrical properties and the photocatalytic elimination efficiency for atrazine (AT, can make feminization of male frogs in the wild, and even induce reproductive cancers in humans.) has been greatly improved compared with the pristine g-C3N4. The results of characterization techniques indicate that the introduced B and P atoms most probably to substitute for sp2-hybridized C atoms in triazine rings. O2− and h+ are the dominant active species to induce the elimination of AT demonstrated by the radical-trapping experiments. And a possible elimination pathway is proposed according to the detected main intermediates. In addition, PB-g-C3N4 was applied to the simultaneous photocatalytic elimination of 9 triazine herbicides, and the effects of different initial concentrations, pH, fulvic acid (FA) and ion species on their elimination effects were studied. And it was proved that the photocatalytic performance of PB-g-C3N4 did not significant decrease after 4 times of reuse.