Chemically synthesized facet-controlled visible light active BiVO4 thin films for photoelectrochemical water splitting

The facile and cost-effective chemical bath deposition (CBD) method is used to synthesize highly photoactive facet-controlled bismuth vanadate (BiVO4) thin films on glass and stainless steel (SS) substrates. The facet-controlled BiVO4 thin films are synthesized by variation in anionic precursor with fine tuning of chemical bath pH from alkaline to acidic media. The variation of anionic precursor evolves the morphology of BiVO4 from dispersed nanoparticles to faceted microcrystals. Furthermore, the fine-tuning of chemical bath pH leads to the well-defined octahedral BiVO4 microcrystals. Compared to dispersed nanoparticulate BiVO4 photoanodes, the octahedral BiVO4 photoanodes demonstrated superior photocurrent density of 2.75 mA cm(-2) (at 1.23 V vs. RHE), good photostability and charge separation efficiency (45.5%) owing to their excellent PEC reaction kinetics. The present study underscores the usefulness of the CBD method for facet-controlled synthesis of semiconducting thin films for different photo-functional applications.

Automated summary

The facile and cost-effective chemical bath deposition method was used to synthesize highly photoactive facet-controlled bismuth vanadate thin films. By fine-tuning the chemical bath pH and anionic precursor, the morphology and structure of the thin films were controlled. The facet-controlled BiVO4 photoanodes showed superior photocurrent density and stability compared to the dispersed nanoparticulate counterparts.