%X Indium gallium nitride (InGaN) is an attractive semiconductor, with a tunable direct bandgap for photoelectrochemical water splitting, but it corrodes in aqueous electrolytes. Cobalt oxide (CoOx) is a promising cocatalyst to protect photoelectrodes and accelerate the charge transfer. CoOx is earth-abundant and stable in extremely alkaline conditions and shows high activity for the oxygen evolution reaction (OER). In this work, we demonstrate that CoOx directly deposited onto InGaN/GaN multiple quantum well photoanodes exhibits excellent activity and stability in a strong alkaline electrolyte, 1 M NaOH (pH = 13.7), for water oxidation up to 28 h, while a reference sample without the catalyst degraded rapidly in the alkaline electrolyte. Under simulated solar illumination, the CoOx-modified InGaN/GaN quantum well photoanode showed a high photocurrent density of 1.26 mA cm–2 at 1.23 V and an onset potential of −0.03 V versus a reversible hydrogen electrode.
%A M Alqahtani
%A S Sathasivam
%A A Alhassan
%A F Cui
%A S Benjaber
%A C Blackman
%A B Zhang
%A Y Qin
%A IP Parkin
%A S Nakamura
%A H Liu
%A J Wu
%T InGaN/GaN Multiple Quantum Well Photoanode Modified with Cobalt Oxide for Water Oxidation
%O This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
%D 2018
%L discovery10073811
%K indium gallium nitrides; quantum wells; photoelectrochemical water splitting; photoanodes; cobalt oxides
%V 1
%N 11
%J ACS Applied Energy Materials
%P 6417-6424