Ionic liquid assisted preparation of phosphorus-doped g-C₃N₄ photocatalyst for decomposition of emerging water pollutants

Phosphorus doped g-C₃N₄ (P/g-C₃N₄) polymer has been prepared by using ionic liquid 1-Butyl-3-methylimidazolium hexafluorophosphate providing the P source. P/g-C₃N₄ shows a high photoactivity for photodecomposition of methylene blue and tetracycline hydrochloride as an emerging water pollutant. The photocatalytic activity of optimized 3%-P/g-C₃N₄ sample (3% in mass ratio of P) is 3 times improved compared to g-C₃N₄. This improvement in activities attribute to the new generated energy levels in the bandgap of g-C₃N₄ that originates from the doping of phosphorus. Photoelectrochemical and photoluminescence results confirmed the high charge separation rates and low charge recombination rates after P doping in g-C₃N₄. The present study showed a simple method of preparation of non-metal ions doped porous g-C₃N₄ photocatalysts for the decomposition of antibiotics in polluted water.