DOI: https://doi.org/10.29363/nanoge.hfuture.2024.009
Publication date: 27th February 2024
In the quest for effective and sustainable photoelectrochemical devices, BiVO4 has emerged as a promising candidate for use as a photoanode material, owing to its favorable band structure for facilitating water oxidation. Addressing challenges such as poor charge transport and sluggish kinetics inherent in BiVO4 photoanodes, SnO2 films have conventionally been utilized as electron transport layers due to their capability to block holes. However, this approach has faced obstacles, including the presence of high defect concentrations at the SnO2/BiVO4 interface and the occurrence of pinholes in SnO2 layers, which can result in charge recombination. To tackle these limitations and bolster the efficacy of SnO2 as a hole-blocking layer, we investigated the impact of ZrCl4 treatment on BiVO4 photoanodes. Through comprehensive characterizations and performance assessments, our findings reveal that ZrCl4 treatment substantially enhances the hole-blocking properties of SnO2, thereby leading to a significant improvement in the overall efficiency of the photoanode. Notably, the implementation of the ZrCl4 treatment method resulted in a 37% increase in photocurrent density (measured at 1.23 V vs. the reversible hydrogen electrode under 1 sun illumination) and a 40 mV shift in the onset voltage.