(29e) Cooperative Effect of Co and Zr Co-Doping on the Photoelectrochemical Water Splitting Performance of Hematite

The energy crisis results in the increased demand for clean fuels such as hydrogen energy. One of the most promising methods to produce hydrogen is photoelectrochemical water splitting, which realizes the conversion from solar energy to chemical energy that is stored in hydrogen molecules. Photoanodes play an important role in the photoelectrochemical water splitting process.

Hematite (Fe₂O₃) is considered as a promising photoanode material due to its stability, abundance and suitable band gap for light absorption. However, its intrinsic defects, such as poor conductivity, suppress the water splitting performance. Doping is a useful way to improve the conductivity of hematite. In this work, Co and Zr are incorporated into iron oxide through in-situ synthesis. Co doping exhibits a positive effect on the hematite photoelectrocatalytic activity, while Zr doping lowers the activity slightly. Furthermore, the cobalt and zirconium co-doped Fe₂O₃ photoanode shows a better performance for photoelectrochemical water oxidation than that of Co doped photoanode. The photocurrent density of co-doped Fe₂O₃ reaches 0.55 mA cm^-2 at 0.23 V (vs. AgCl), which is increased by 27.9% compared with the raw Fe₂O₃. This result reveals the cooperative effect between Co and Zr on improving the Fe₂O₃ performance towards water oxidation.