Molecular cathode and photocathode materials for hydrogen evolution in photoelectrochemical devices

Storage of solar energy in the form of readily available easy-to-handle fuels is the main bottleneck toward the development of a carbon-neutral alternative energy. Taking inspiration from natural systems, artificial photosynthesis is a technology to be for efficiently converting the tremendous solar energy received every day on Earth into chemical energy, i.e. fuels. In particular, hydrogen production through light-driven water splitting is the subject of numerous investigations. We focus here on the construction of electrodes and photoelectrodes achieving H-2 evolution, as components of photoelectrochemical (PEC) cells. In such devices, H-2 evolution at the cathode or photocathode is combined with water oxidation to oxygen at the photoanode or anode. We review here the various molecular-based materials developed in this context with emphasis on those specifically exploiting the properties of Earth-abundant elements. (C) 2015 Elsevier Ireland Ltd. All rights reserved.