MXene Boosted CoNi-ZIF-67 as Highly Efficient Electrocatalysts for Oxygen Evolution

Abstract

Oxygen evolution reaction (OER) is a pivotal step for many sustainable energy technologies, and exploring inexpensive and highly efficient electrocatalysts is one of the most crucial but challenging issues to overcome the sluggish kinetics and high overpotentials during OER. Among the numerous electrocatalysts, metal-organic frameworks (MOFs) have emerged as promising due to their high specific surface area, tunable porosity, and diversity of metal centers and functional groups. It is believed that combining MOFs with conductive nanostructures could significantly improve their catalytic activities. In this study, an MXene supported CoNi-ZIF-67 hybrid (CoNi-ZIF-67@Ti3C2Tx) was synthesized through the in-situ growth of bimetallic CoNi-ZIF-67 rhombic dodecahedrons on the Ti3C2Tx matrix via a coprecipitation reaction. It is revealed that the inclusion of the MXene matrix not only produces smaller CoNi-ZIF-67 particles, but also increases the average oxidation of Co/Ni elements, endowing the CoNi-ZIF-67@Ti3C2Tx as an excellent OER electrocatalyst. The effective synergy of the electrochemically active CoNi-ZIF-67 phase and highly conductive MXene support prompts the hybrid to process a superior OER catalytic activity with a low onset potential (275 mV vs. a reversible hydrogen electrode, RHE) and Tafel slope (65.1 mV∙dec−1), much better than the IrO2 catalysts and the pure CoNi-ZIF-67. This work may pave a new way for developing efficient non-precious metal catalyst materials.

Synergistic cerium doping and MXene coupling in layered double hydroxides as efficient electrocatalysts for oxygen evolution

“…MXene is a new group of two-dimensional nanosheets (early transition metal carbides/carbonitrides), characterized by its excellent electrical conductivity and surface hydrophilicity [20 , 21] . Previous reports have demonstrated the improved catalytic activity when coupling MXene with the electrocatalytically active phases, such as graphitic C 3 N 4 /MXene hybrid film [22] , Co-BDC/MXene [23] , MoS 2 /MXene [24] , FeNC/MXene [25] and ZIF-67/MXene hybrids [26] . Nevertheless, the development of MXene-based LDH hybrid systems is still in a preliminary stage compared with the prosperity of carbon-supported LDH composites.…”

Recent Progress in MXene‐Based Materials: Potential High‐Performance Electrocatalysts

“…The Ti 3 C 2 T x -CoBDC composite combines the hydrophilicity and electrical conductivity of Ti 3 C 2 T x with the multi-channel and multi-active sites of 2D MOFs, effectively promoting electron transfer and mass transfer process, and has excellent electrocatalytic activity for OER compared with that of the commercial IrO 2 catalyst. In addition, Wen et al [91] synthesized MXene-supported CoNi-ZIF-67 hybrid (denoted as CoNi-ZIF-67@Ti 3 C 2 T x ) by co-precipitation reaction. The results show that the inclusion of the MXene matrix not only produces smaller CoNi-ZIF-67 particles, but also increases the average oxidation of Co/Ni elements, making the CoNi-ZIF-67@Ti 3 C 2 T x as an excellent OER electrocatalyst.…”

Modulating Metal–Organic Frameworks as Advanced Oxygen Electrocatalysts

“…Similarly, several other examples of MOFs/graphene (or rGO) composites also exhibited much enhanced electrocatalytic activities for OER or ORR. [ 94–98 ] Besides graphene or rGO, it is also feasible to fabricate MOFs composites with other conductive materials, including activated carbon (AC), [ 99 ] Mxene, [ 100,101 ] CNTs, [ 102–104 ] carbon black, [ 105 ] and Ag nanowires. [ 106 ] The obtained composite usually exhibited greatly enhanced electrocatalytic activities compared with the pure MOF owing to the synergistic effect between the two components that facilitate the electrochemical processes.…”