Solar Light as the Energy Source for the Generation of Clean and Renewable Fuel: A View on the Photoelectrocatalytic Water Splitting

The pursue of clean and renewable energy sources to substitute those originated from fossil resources has been one of the major challenges of the modern society. One of the most promising and sophisticated approach to accomplish this target is the generation of hydrogen gas from the solar-light-driven split of water catalyzed by inexpensive and stable photocatalysts. Hydrogen can be employed as fuel for vehicles and other transportation means, and also as feedstock for valuable industrial processes. This review article focuses on the exposition and the discussion of the principles that govern the photocatalytic water splitting for the generation of hydrogen using semiconductors composed of earth-abundant elements as photocatalysts. It also explains the operation basics of photoelectrocatalytic cells and exposes the most stringent bottlenecks faced by scientists of the field, discussing some strategies to circumvent them. Some examples of promising photoanodes and photocathodes employed in photoelectrocatalytic water splitting are also given.