CaBi6O10: a novel promising photoanode for photoelectrochemical water oxidation

Novel CaBi6O10 films were prepared via a simple dip-coating method and applied as a photoanode in photoelectrochemical (PEC) water splitting for the first time. Herein, the detailed growth mechanism of CaBi6O10 has been discussed. The optical absorption of CaBi6O10 was also investigated, and the results indicated that its ideal band-gap energy (∼2.3 eV) causes it to respond to visible light. Additionally, the morphology and thickness of the films were characterized in detail. PEC measurements showed that this CaBi6O10 photoanode exhibits high photoelectrochemical activity based on the optimal pH value of the precursor solution and thickness of the film; its photocurrent density is as high as 0.39 mA cm−2 at 1.23 V vs. RHE under simulated sunlight. Moreover, the CaBi6O10 photoelectrode displays a very stable photoelectric property under illumination. The excellent PEC performance is attributed to the excellent light absorbance, broad photoresponse range, and efficient photogenerated electron–hole pair separation of CaBi6O10. These results demonstrate that CaBi6O10 is a promising photoanode for solar water splitting.