Visible-LEDs-induced enhanced photocatalytic and antibacterial activity of BiVO4-based green photocatalysts decorated with silver and graphene.

[Display omitted] • BiVO 4 nanostructures were prepared with an environmentally responsible methodology. • Green procedures were used to decorate with nitrogen-doped graphene and silver NPs. • Novel N-G/Ag/BiVO 4 exhibited the best photoinactivation of pathogenic microorganisms. • Novel N-G/Ag/BiVO 4 NS exhibited the highest performance in the CV degradation. • Photocatalytic activity achieved was using inexpensive and low-power blue LEDs. Bismuth vanadate (BiVO 4) is an attractive compound because of its visible light photocatalytic activity with a narrow energy gap of less than 2.4 eV. In addition, it has favorable band edge positions and is stable in an aqueous environment. Its photocatalytic activity can be translated for potential use for degradation of organic matter. To assess this activity, BiVO 4 combined with graphene (N-G/BiVO 4), silver (Ag/BiVO 4), or both of them (N-G/Ag/BiVO 4) were synthesized. These nanostructures (NSs) were characterized using physicochemical analyses. The NSs were tested for their capabilities to photodegrade crystal violet and inactivate bacteria. Results showed that N-G/Ag/BV exhibited the highest activity for degrading crystal violet, reaching 100 % of photodegradation within 60 min of light exposure, while N-G/BiVO 4 , BiVO 4 and Ag/BiVO 4 achieved 81, 89 and 95 % within 180 min, respectively. In the case of bacterial inactivation, the Ag/BiVO 4 NS completely photoinactivated E. coli within 60 min. The main oxidative species acting in the E. coli photoinactivation and CV photodegradation over the Ag/BiVO 4 and N-G/AgBiVO 4 NSs were identified as •O 2 – and h+. Also, the chemical stability and effective re-use of the photocatalysts were evaluated. In conclusion, the Ag/BV and N-G/Ag/BV catalysts possess high stability, making them potential candidates for wastewater treatment. [ABSTRACT FROM AUTHOR]