Editors' Choice-Review-Creating Electrocatalytic Heterojunctions for Efficient Photoelectrochemical CO2 Reduction to Chemical Fuels

Artificial photosynthesis can potentially address the global energy challenges and environmental issues caused by fossil fuels. Photoelectrochemical heterojunction structures of new photonic structures have been developed for efficient sunlight absorption, charge generation and separation and transport, and selective reduction of CO2 and water splitting. In this review, an overview of several recently developed heterojunction model systems comprised of low-cost photonic materials such as transition metal dichalcogenides (TMDs), perovskite semiconductor nanocrystals, and plasmonic nanostructures is presented to rationalize the potential benefits of utilizing heterojunction structures for efficient and selective CO2 reduction with renewable energy resources. Recent advances in electroanalytical methods for CO2 reduction such as scanning electrochemical microscopy (SECM) are reviewed. These techniques can potentially resolve local CO2 reduction kinetics and their spatial heterogeneities of a heterojunction photoelectrochemical structure.