Abstract
We studied H2 gas generation using a GaN photoelectrode in both HC1 and KOH solutions. The photocurrent in KOH was larger than that in HCl under a small extra bias, and caused a more extensive H2 generation at the beginning. GaN corrosion in HCI was less extended than that in KOH during photoelectrochemical reactions. The stability of the GaN photoelectrode in HCI was a result of H2O reduction and Cl- oxidation instead of water photoelectrolysis.