Photoelectrochemical Energy Conversion over 2D Materials

The solar motivated photoelectrochemical (PEC), used in water splitting systems, shows superior talent in converting solar energy in the form of cleaning and in sustaining a chemical energy evolution. PEC systems present by integrating a photoelectrode, which involves light-harvesting to absorb solar energy, thereby introducing an interlayer for the transformation of photogenerated electrons and holes, along with a co-catalyst to trigger oxidation and reduce the chemical reactions. In this review, we describe a variety of two-dimensional (2D) layered photoanodes and photocathodes, such as graphitic carbon nitrides, transition metal dichalcogenides, layered double hydroxides, MXenes, and co-catalysts for the assembly of combined photoelectrodes belonging to oxygen evolution and/or hydrogen evolution chemical reactions. The basic principles of PEC water splitting associated with physicochemical possessions relating to photoelectrodes unified with catalytic chemical reactions have been investigated. Additionally, the mechanisms attributing to a relationship with 2D photoelectrodes have been incorporated as a supplementary discussion. The improvement strategies, which include the construction of heterostructures, surface functionalization, and formations of heterojunctions, have also been discussed. The issues and challenges relevant to the field have been acknowledged for facilitating future research, indicating optimized conversion activity corresponding to PEC water splitting.