Photothermal-assisted solar hydrogen production: A review

Abstract

Hydrogen energy is widely regarded as one of the most promising clean energy sources to address contemporary energy and environmental challenges. Hydrogen production via solar energy facilitates the decoupling of energy supply and demand, thereby mitigating the intermittency and instability inherent in solar energy utilization. In the process of solar-driven hydrogen production, a substantial portion of solar energy is inevitably dissipated as heat due to material and system limitations. Therefore, the utilization of solar thermal energy to construct photothermal-assisted solar hydrogen production systems is of paramount importance for enhancing solar energy utilization efficiency. This paper provides a comprehensive review of the latest advancements in photothermal-assisted solar hydrogen production systems, with a focus on the application of photothermal effects in diverse solar hydrogen production systems. It offers an in-depth analysis of the mechanisms by which photothermal effects enhance the process, including photothermal excitation of pyroelectric effects, suppression of hydrogen–oxygen recombination, and enhancement of polaron transport. Additionally, the paper reviews strategies for the integration of solar thermal energy into solar-coupled hydrogen production systems. Subsequently, evaluation metrics for photothermal-assisted solar hydrogen production are proposed, accompanied by a comparative analysis of various photothermal-assisted solar hydrogen production systems. Finally, the prospects and challenges of photothermal-assisted solar hydrogen production are discussed, providing a comprehensive outlook to guide future research in this field.