Recent Development in Solar-to-Hydrogen Conversion Systems

Abstract

The sustainable future can be realized by utilizing solar energy and converting it to different forms of energy that can be effectively stored. Hydrogen (H2) and its derivatives are widely regarded as future energy carriers essential for achieving a sustainable and decarbonized energy system. One of the most promising approaches to produce clean H2 is by converting solar energy directly into chemical energy via water splitting. This can be achieved using photoelectrochemical processes that harness sunlight to produce H2 from water (H2O). There are three primary solar-driven pathways for hydrogen generation: photocatalysis (PC), photoelectrochemical cells (PEC), and photovoltaic–electrochemical (PV–EC) systems. This review provides a systematic comparison of these methods by examining their operating principles, materials, stability, and solar-to-hydrogen (STH) conversion efficiency, offering insights into their scalability and suitability for sustainable hydrogen production. The research on these conversion systems is widely spread across different fields, and experimental works were done under different standards. These works are unintegrated and very few works have systematically compared them to benchmark their performances. In this work, we systematically review three different systems by examining their working mechanism, materials, stability, and efficiency, providing insights into their potentials for large-scale, sustainable hydrogen production. This work provides evidence-based insight into different technologies to help different stakeholders and decision makers. We observed the triple-junction PV-EC system exhibit 30% STH with exceptional stability.