Recent progress in material selection and device designs for photoelectrochemical water-splitting

The development of renewable and sustainable energy sources along with efficient storing strategies has been the focus of utmost importance within the community to address the current energy crisis and rising energy demands. In this respect, solar hydrogen production through the route of photoelectrochemical (PEC) water-splitting is considered as a highly promising option. This review begins with a focus on understanding the PEC fundamentals in terms of the charge-transfer processes and energy requirements followed by the prerequisite properties of photoelectrode materials. We then highlighted the recent progress in different semiconductor materials and PEC device configurations. Various photoelectrode materials and device designs were classified based on their performances, with the realization of their advantages and limitations. Recent investigations in theoretical studies carried out in this field were summarised to understand the knowledge-gap and futuristic requirements. Challenges responsible for the limited efficiencies of the existing PEC water-splitting technology, considering both the material development and PEC device designs, have been discussed. Accordingly, certain possible strategies and solutions were recommended with an aim to make the PEC water-splitting a practically feasible technology.