Abstract
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•Ag3VO4 was anchored onto P and S co-doped g-C3N4 to form type II photocatalyst.•Photocatalyst formed a stable and well-dispersed suspension in water for 3 h.•Phenol was completely photo-mineralized from water in 6 h under visible light.•Stable photocatalyst was recycled with no significant activity loss for ten cycles.•Photocatalyst deactivated 99% of E. coli bacteria in 60 min under visible light.
In this work, we have successfully anchored Ag3VO4 (AV) onto P and S co-doped g-C3N4 (PSGCN) to prepare high-dispersible AV/PSGCN photocatalyst via a deposition-precipitation method. The P and S co-doped g-C3N4 was synthesized via thermal polycondensation using hexachlorotriphosphazene (HCCP) and thiourea as precursors. AV/PSGCN was characterized using various spectral techniques. The atomic force analysis indicated that the thickness of AV/PSGCN was less than 3.0 nm. The zeta potential and Tyndall effect experiments ascertained formation of the well-dispersed suspension of AV/PSGCN in water. The co-doping resulted in lowering optical band gap of g-C3N4. The photoluminescence and electrochemical impedance analysis indicated suppression in recombination of photogenerated electron and hole pairs in AV/PSGCN. The photodegradation of phenol followed pseudo-first order kinetics. Hydroxyl radicals and holes were the two main reactive species for photodegradation of phenol. The COD, HPLC and LC-MS analyses confirmed mineralization of phenol in 6 h. Unlike conventional slurry type photo-reactors, AV/PSGCN was not magnetically agitated during photocatalytic reactions. AV/PSGCN exhibited significant antibacterial activity for E. coli disinfection. The photodegradation of phenol and bacterial disinfection occurred through hole and hydroxyl radical formation mechanism.