Strategies and implications of atomic layer deposition in photoelectrochemical water splitting: Recent advances and prospects

Presently, photoelectrochemical (PEC) water splitting is the most promising way to generate hydrogen in a clean and sustainable manner. However, enormous challenges need to be overcome in order to improve the efficiency of solar water splitting, which are attributed to the energy lost during the essential light-harvesting process, a result of the recombination of photogenerated charge carriers and the concomitant degradation of fabricated electrodes. Interfacial interactions between the electrode and electrolyte are crucial factors that govern the stability and the charge-transfer phenomena that affect overall PEC efficiency. With the advent of advanced engineering techniques, post-surface modification using atomic layer deposition (ALD) has garnered research attention because it can facilitate the development of nanostructure materials on the atomic scale, engineering of bandgaps, passivation of surfaces, improvement of catalysts, and modification of the light-harvesting properties of a surface. The present review focuses on exploiting ALD to improve the structural and surface properties of designed electrodes through the use of various ALD-deposited materials and on understanding their effects on PEC efficiency as well as provides a brief discussion on the fundamentals of PEC. Recent ALD projections that have contributed to enhancing the activities of PEC devices are also highlighted. Furthermore, this review summarizes the future outlook and potential of PEC water splitting, which has gained considerable interest in the current research sector.

Automated summary

PEC water splitting is a promising method to generate hydrogen, but challenges remain in improving efficiency, such as energy loss during light-harvesting and electrode degradation. Interfacial interactions between electrode and electrolyte are crucial for overall efficiency. Post-surface modification using ALD has attracted attention for enhancing PEC efficiency.