Enhanced Water Splitting Stability with Controlled NiO Co-Catalyst on GaN Photoanode

Arrayed NiO co-catalyst on GaN is proposed to improve water splitting efficiency and to obtain stable photoelectrolysis without dissolution of photoanode. The characteristics of photoanodes were investigated by changing the height of NiO on n-GaN. The photoanode stability and performance of GaN with NiO was significantly improved compared to the reference GaN at zero bias. SEM measurements showed negligible etching of NiO and GaN surfaces, which confirmed considerably improved stability compared to the reference n-GaN. In summary, enhanced water splitting efficiency and photoanode stability were achieved by combining GaN with NiO co-catalyst which are advantageous for water splitting applications.