Research Progress of Nickel-Based Metal-Organic Frameworks and Their Derivatives for Oxygen Evolution Catalysis

Abstract

As one of the most promising hydrogen production technologies, electrochemical water splitting is an effective measure for solving environmental pollution and energy crises. However, the slow kinetics and high overpotential of the oxygen evolution reaction (OER) are the primary deterrents for improving the efficiency of water splitting devices. Iridium- and ruthenium-based noble metal catalysts are extremely expensive, which limits the industrial-scale development of this technology. Therefore, the development of oxygen evolution catalysts with high activity, excellent stability, and low costs is significantly important for water splitting technologies. Nickel-based materials meet the requirements of high abundance, cost-effectiveness, and high activity. In recent years, nickel-based metal organic frameworks (Ni-based MOFs) have attracted increasing research attention owing to their diverse and tunable topological structures and large specific surface areas. Furthermore, the mesoporous three-dimensional structure of MOFs can promote the diffusion of reactants, rendering them excellent candidates for catalytic applications. In order to utilize the advantages of Ni-MOFs more efficiently, the following methods are usually used to improve their catalytic performance. Owing to their unique properties, metal nodes can be replaced without affecting the MOF skeleton. As iron series metals, Co and Fe doping show unique catalytic activity and structural stability due to the synergistic effect between metal centers. Further, Ni-MOFs can simultaneously be used as precursors for oxidation, phosphating, or vulcanization to obtain Ni-MOF derivatives with different components. Among them, high-temperature carbonization treatment can make use of abundant organic ligands of Ni-MOFs to form a partially graphitized carbon-based framework, thereby augmenting conductivity, preventing the aggregation and corrosion of transition metals, and improving the overall support strength. The catalytic performance of oxygen production can be further improved by directly growing the Ni-MOFs on the substrate and introducing other active substances or conductive materials. Herein, the latest developments of Ni-based MOFs and their derivatives have been reviewed with regard to their utilization in OER catalysis, including nickel oxides, nickel hydroxides, nickel phosphides, nickel sulfides, and carbon composite materials. First, the mechanism and measurement criteria of the OER are briefly introduced. Second, the structures of several typical Ni-based MOFs (MOF-74, MILs, PBAs, and ZIFs) and their preparation methods are described. Subsequently, recent advances in the application of Ni-based MOFs and their derivatives in the OER are discussed, with an emphasis on materials design strategies and catalytic mechanisms. Finally, the main challenges and opportunities in this field are proposed.