Enhanced photocatalytic performance of BiVO4 in aqueous AgNO3 solution under visible light irradiation

Abstract Monoclinic-phase bismuth vanadate (BiVO 4 ) with a 2.468 eV band gap exhibited enhanced synergic photodegradation activity toward methylene blue (MB) when combined with silver ions (Ag + ) in an aqueous solution under visible light irradiation. The mass ratio of AgNO 3 to BiVO 4 and the calcination temperature were discovered to considerably affect the degradation activity of BiVO 4 /Ag + . Superior photocatalytic performance was obtained when BiVO 4 was mixed with 0.01%(w/v) AgNO 3 solution, and complete degradation of MB was achieved after 25 min visible light irradiation, outperforming BiVO 4 or AgNO 3 solution alone. The enhanced photodegradation was investigated using systematic luminescence measurements, electrochemical impedance spectroscopy, and scavenger addition, after which a photocatalytic mechanism for MB degradation under visible light irradiation was identified that involved oxygen radicals and holes. This study also discovered the two dominating processes involved in enhancing the electron–hole separation efficiency and reducing their recombination rate, namely photoreduction of Ag + and the formation of a BiVO 4 /Ag heterojunction. The synergic effect between BiVO 4 and Ag + was discovered to be unique. BiVO 4 /Ag + was successfully used to degrade two other dyes and disinfect Escherichia Coli . A unique fluorescent technique using BiVO 4 and a R6G solution to detect Ag + ions in water was discovered.