Bismuth Iron Oxide Nanoparticles as Photocatalyst for Solar Hydrogen Generation from Water

Multiferroic materials such as bismuth iron oxide (BiFeO3/BFO) have strong potential for solar hydrogen generation. In this paper, we have described a sol-gel method using urea and polyvinyl alcohol at low temperature to synthesize high purity BFO nanoparticles of size 50- 60 nm. A complicated and high temperature process is usually employed to synthesize BFO. It is observed that the material has an energy band gap of 2.1 eV which makes it a potential material towards solar applications. Photoelectrochemical (PEC) and photocatalytic tests are conducted to evaluate BFO's performance towards hydrogen generation by splitting of water using simulated solar light. PEC generation of hydrogen using fabricated electrodes (BFO nanoparticles coated on titanium foil) shows that the material is photoactive and can evolve hydrogen from water using a visible light. Photocatalytic tests for hydrogen generation are also performed using the nanoparticles in 1(M) KOH solution under simulated solar light. Upon analysis of the evolved gases by gas chromatography (GC), hydrogen and oxygen are detected. Furthermore, it is also observed that BFO generates three times more hydrogen than commercial titania P25 catalyst under similar experimental conditions.