Compositional Engineering of Co(II)MOF/Carbon-Based Overall Water Splitting Electrocatalysts: From Synergistic Effects to Structure–Activity Relationships

Ranging from structure to property, the design of reasonable structures leading to high-performance electrochemical properties has enabled metal–organic frameworks (MOFs) to have great achievement in energy conversion. Since Co(II) has multiple valence states and is especially abundant, CoMOFs have emerged as latent materials of electrocatalysts in overall water splitting. In fact, CoMOFs/carbon-based hybrid materials (Co/CHMs) exhibit all kinds of architectures, marvelous electrochemical capabilities, and synergistic effects, overcoming the relative insulation of CoMOFs and single structure carbon materials. The synergistic effect of CoMOFs-based materials and carbon materials forming a unique interface can increase the specific surface area and accelerate electron transfer rates, resulting in enhanced overall water splitting. In terms of this review, the various Co/CHMs (carbon = GO/RGO, CNT, and carbon black) are summarized. The relationship between the synergistic effect of Co/CHMs and the activity of overall water splitting is discussed. Finally, this review can supply a certain degree of reference for Co/CHMs as electrocatalysts in the field of overall water splitting and a number of helpful comments for prospective energy materials.