We describe the synthesis of bismuth vanadate nanoflowers decorated with Au nanoparticles (Au-BiVO4NF) using conventional oil bath or microwave irradiation as a heating source, where de AuNPs exhibit sizes of 29 ± 10 nm and 50 ± 11 nm. We show how microwaves can be used to replace well-stablished methods in the synthesis of inorganic nanomaterials and drastically reduce both time and energy consumptions. The Au-BiVO4NF obtained under microwave irradiation exhibited the same physical-chemical properties of those prepared through conventional heating; however, time lapse for synthetizing the heterojunction decreased from 4 h to only 10 min. The heterojunction is a very promising photocatalyst under visible light irradiation since BiVO4 exhibits low band-gap energy and Au nanoparticles can behave as electron sinks and/or as electron sources through plasmon resonance, increasing charge separation of photogenerated electrons and holes. This synergic effect resulted in a heterojunction able to degrade ~ 95% of methylene blue after 6 h of UV-visible light irradiation.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.