Porphyrin-based heterojunction photocatalysts: design principles and applications in solar-to-chemical energy conversion

Abstract

As global climate change and energy crises continue to escalate, the development of efficient solar energy conversion technologies has become imperative for addressing pressing environmental and energy-related challenges. Porphyrin-based materials, renowned for their exceptional light-harvesting capabilities and tunable electronic structures, have emerged as promising candidates in the field of photocatalysis. Nevertheless, individual porphyrin-based photocatalysts are still constrained by rapid charge carrier recombination and limited long-term stability. Heterojunction engineering, leveraging the synergistic effects of interfacial design and internal electric fields, offers an effective strategy to facilitate charge separation and migration, thereby significantly enhancing photocatalytic performance. This review provides a comprehensive overview of the design strategies of porphyrin-based heterojunctions, with a particular focus on charge transfer mechanisms in different heterojunction architectures and their influence on photocatalytic activity. We systematically explore the integration of porphyrin-based materials with various semiconductors, including g-C₃N₄, metal oxides and metal sulfides, as well as the construction of porphyrin-based MOFs and COFs and their hybridization with semiconductor materials. These approaches have demonstrated considerable potential in driving photocatalytic hydrogen evolution and CO₂ reduction. Finally, we discuss the current challenges and future perspectives for developing porphyrin-based heterojunction photocatalysts, emphasizing interfacial modulation, stability improvement, selectivity enhancement, cost-effectiveness, and in-depth mechanistic understanding. This review aims to offer valuable insights into the fundamental principles and practical applications of porphyrin-based heterojunctions for solar-to-chemical energy conversion, thereby fostering further progress in this promising research domain.