Recent advances in InGaN nanowires for hydrogen production using photoelectrochemical water splitting

Photoelectrochemical (PEC) water splitting is a promising approach for hydrogen production using solar energy with zero emissions. However, the solar-to-hydrogen efficiency (STH) of the practical PEC systems (∼10%) is far from the theoretical value (<25%). However, the key barrier to improving STH efficiency is the lack of high-performance and chemically stable photoelectrodes. In recent years, InGaN nanowires have emerged as a promising solution in designing efficient photoelectrodes for PEC water splitting. Their tunable band gap, excellent chemical stability, and high catalytic activity make them strong candidates for PEC applications. Yet, these systems do not yield the STH efficiencies required for commercial applications. The primary purpose of this article is to provide a comprehensive literature review of the advances in InGaN nanowires for the production of H2 via photoelectrochemical water splitting. The first sections of this article present the working principle of PEC water splitting using InGaN nanowires and the recent approaches to growing well-elongated InGaN nanowires. Then, the paper discusses strategies that can enhance the stability and efficiency of this technology, in addition to reducing the fabrication cost of InGaN NW photoelectrodes via the reuse of the growth substrate by employing the h-BN lift-off transfer technique.