Effects of NiO-loading on n-type GaN photoanode for photoelectrochemical water splitting using different aqueous electrolytes. (13th April 2017)

• Record Type: Journal Article
• Authors: Koike, Kayo; Yamamoto, Kazuhiro; Ohara, Satoshi; Kikitsu, Tomoka; Ozasa, Kazunari; Nakamura, Shinichiro; Sugiyama, Masakazu; Nakano, Yoshiaki; Fujii, Katsushi
• Is Part Of: International journal of hydrogen energy. Volume 42:Number 15(2017)
• Page Start: 9493
• Page End: 9499
• Publication Date: 2017-04-13
• Subjects: GaN -- Photoanode -- Water splitting -- Anodic corrosion -- NiO; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2016.12.141
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: n-type GaN photoanodes used for water splitting have stability problems. One means of resolving this is loading NiO catalyst on the n-type GaN surface. Aqueous electrolytes H2 SO4, HCl, KOH, and NaOH are usually used for photoelectrochemical water splitting. However, suitable electrolytes for the NiO-loading on n-type GaN photoelectrode have not yet been evaluated. Therefore, we investigated the effects of changing electrolytes used for NiO-loading in this study. The photocurrent of NiO-loading on n-type GaN increased when KOH and NaOH electrolytes were used. In addition, the surfaces showed no corrosion after reaction when these electrolytes were used. However, the photocurrent was not stable using KOH electrolyte. Interestingly, stable photocurrent was observed with when the NaOH electrolyte was used. In the case of H2 SO4, the photocurrent of GaN did not change with and without NiO. The surface morphologies became rough because of GaN corrosion, and NiO dissolved in the H2 SO4 electrolyte. Highlights: New NiO-loading method on n-type GaN by using Ni(OH)2 dispersion. Superior catalytic performance of NiO-islands on GaN photoanode for water splitting. Photoelectrochemical properties of n-type GaN with NiO in different electrolyte.