Synthesis of bismuth vanadate: its application in H₂evolution and sunlight-driven photodegradation

A nanocrystalline m-BiVO4 photocatalyst for H2 evolution, which works under UV-light irradiation, has been synthesized by a facile solution combustion synthesis method. Hydrogen evolution over BiVO4 is a significant result in the field of renewable energy sources and here we are the first to show hydrogen evolution experimentally with BiVO4 in the absence of either coupling oxides or doping metals. The yield of hydrogen generated is about 489 μmol per 2.5 h of reaction under UV irradiation. The ultra-light yellow crystalline combustion derived nanopowder exhibits porous morphology with a strong absorption in the visible light region. The estimated band gap of BiVO4 powder is about 2.52 eV. The powder shows highly visible photocatalytic activity towards methylene blue degradation under sun light irradiation. The H2 evolution and photocatalytic activity of BiVO4 nanocrystalline powder can be attributed to its physical properties such as nanosize particles and large surface area.