BiVO4 Ceramic Photoanode with Enhanced Photoelectrochemical Stability

Monoclinic bismuth vanadate (BiVO4) is an attractive material with which to fabricate photoanodes due to its suitable band structure and excellent photoelectrochemical (PEC) performance. However, the poor PEC stability originating from its severe photo-corrosion greatly restricts its practical applications. In this paper, pristine and Mo doped BiVO4ceramics were prepared using the spark plasma sintering (SPS) method, and their photoelectrochemical properties as photoanodes were investigated. The as-prepared 1% Mo doped BiVO4ceramic (Mo-BVO (C)) photoanode exhibited enhanced PEC stability compared to 1% Mo doped BiVO4films on fluorine doped Tin Oxide (FTO) coated glass substrates (Mo-BVO). Mo-BVO (C) exhibited a photocurrent density of 0.54 mA/cm2and remained stable for 10 h at 1.23 V vs. reversible hydrogen electrode (RHE), while the photocurrent density of the Mo-BVO decreased from 0.66 mA/cm2to 0.11 mA/cm2at 1.23 V vs. RHE in 4 h. The experimental results indicated that the enhanced PEC stability of the Mo-BVO (C) could be attributed to its higher crystallinity, which could effectively inhibit the dissociation of vanadium in BiVO4during the PEC process. This work may illustrate a novel ceramic design for the improvement of the stability of BiVO4photoanodes, and might provide a general strategy for the improvement of the PEC stability of metal oxide photoanodes.Keywords:BiVO4photoanode;photoelectrochemical stability;spark plasma sintering (SPS);ceramics