Recent Progress in Gallium Nitride for Photoelectrochemical Water Splitting

Abstract

With the constant consumption of traditional energy sources, it is urgent to explore and develop new energy sources. Photoelectrochemical (PEC) water splitting is a method of preparing energy that can continuously generate hydrogen fuel without pollution to the environment. As an important part of the PEC water splitting system, the choice of semiconductor photoelectrode is crucial. Among these materials, gallium nitride (GaN) has attracted considerable attention due to its tunable band gap, favorable band edge positions, wide band gap, and good stability. In the past years, many reports have been obtained in GaN for PEC water splitting. This review summarizes the GaN as photoelectrodes for PEC water splitting, and methods to improve the efficiency of GaN for PEC water splitting also will be summarized from change morphology, doping, surface modification, and composition of solid solution or multiple-metal incorporation. Eventually, the future research directions and challenges of GaN for PEC water splitting are also discussed.

Effects of surface properties of GaN semiconductors on cell behavior

“…The chemical property of GaN is very stable and almost insoluble in water, acid, and alkali solutions at room temperature and pressure, except for an electrochemical environment [ 13 , 14 ]. Under high-temperature conditions, concentrated phosphoric acid, concentrated sulfuric acid or molten caustic soda will etch the GaN surface [ [15] , [16] , [17] ].…”