Rational Design of Photoanodes to Produce Value-Added Chemicals Coupled with Hydrogen

Green hydrogen fuel generation via the photoelectrochemical (PEC) approach has attracted considerable attention recently for its sustainability and eco-friendliness. Photoelectrocatalysts are the key component of the PEC process. To produce green hydrogen by this approach at a reasonable rate from water splitting and waste valorization, proper design and electronic structure modulation of the photoelectrocatalysts are of utmost importance. Therefore, in this review, we discuss the materials selection, design, and engineering of photoanode materials to efficiently harvest and convert solar energy into green hydrogen fuel and value-added chemicals. In this regard, we introduce the fundamentals and the mechanistic insights of the PEC solar energy conversion and storage technologies, which would provide knowledge to novices to gain insight into this field while designing a new photoanode. Moreover, we mention the importance of various semiconducting materials and their surface/interface engineering aspects to improve the PEC properties for selective water oxidation to value-added chemicals and waste valorization coupled with green hydrogen generation. Finally, we discuss the conclusions and prospects of this technology by highlighting the major challenges and its potential for commercialization.