Metal–Organic Framework-Derived Co₃ZnC/Co Embedded in Nitrogen-Doped Carbon Nanotube-Grafted Carbon Polyhedra as a High-Performance Electrocatalyst for Water Splitting

Abstract

The development of efficient, low-cost, and stable electrocatalysts for overall water splitting is of great significance for energy conversion. Transition-metal carbides (TMCs) with high catalytic activity and low cost have attracted great interests. Nevertheless, utilizing an efficient catalyst for overall water splitting is still a challenging issue for TMCs. Herein, we report the synthesis of a high-performance electrocatalyst comprising CoZnC and Co nanoparticles embedded in a nitrogen-doped carbon nanotube-grafted carbon polyhedral (CoZnC/Co-NCCP) by the pyrolysis of bimetallic zeolitic imidazolate frameworks in a reductive atmosphere of Ar/H. The CoZnC/Co-NCCP exhibits remarkable electrochemical activity in catalyzing both the oxygen evolution reaction and hydrogen evolution reaction, in terms of low overpotential and excellent stability. Furthermore, the CoZnC/Co-NCCP catalyst leads to a highly performed overall water splitting in the 1 M KOH electrolyte, delivering a current density of 10 mA cm at a low applied external potential of 1.65 V and shows good stability without obvious deactivation after 10 h operation. The present strategy opens a new avenue to the design of efficient electrocatalysts in electrochemical applications.

Synthesis of FeNiCo Ternary Hydroxides through Green Grinding Method with Metal‐Organic Frameworks as Precursors for Oxygen Evolution Reaction

“…The overpotentials of different prepared electrodes at 10 and 50 mA cm −2 and corresponding Tafel slopes are contrasted in Figure 3c. It illustrates that G‐FeNi‐Co‐ZIF‐L/NF shows the lowest overpotential of 248 mV at 10 mA cm −2 and the smallest Tafel slope of 49.5 mV dec −1 compared with G‐Fe‐Co‐ZIF‐L/NF (307 mV, 49.6 mV dec −1 ), G‐Ni‐Co‐ZIF‐L/NF (312 mV, 76.8 mV⋅dec −1 ), Co‐ZIF‐L/NF (292 mV, 90.0 mV dec −1 ), RuO 2 /NF (310 mV, 57.8 mV dec −1 ) and NF (411 mV, 135.7 mV dec −1 ), which is also comparable to those of other reported ZIF‐derived electrocatalysts (Figure 3d and Table S1) [40–49] . These results confirm the synergistic effect of the Fe/Ni/Co tri‐metallic material, which can greatly improve the catalytic activity of electrocatalyst towards OER.…”

Designing MOF Nanoarchitectures for Electrochemical Water Splitting

“…In recent times, a versatile strategy for designing highperformance electrocatalysts has been to controllably introduce two different metal species into a single nanostructure, namely Co-NC@ Mo 2 C, [119] Co 3 O 4 -RuCo@NC, [121] NG-NiFe@MoC 2 , [256] Co/Co 9 S 8 @ NSOC, [122] NiO/Co 3 O 4 , [120] Co@Ir/NC, [257] Ni 2 P/CoN-PCP, [258] among others, [92,[259][260][261][262][263][264] to further facilitate and accelerate the activation process of the reactants. For instance, Hu et al synthesized MoC 2 -doped NiFe alloy nanoparticles (NPs) embedded within several-layer-thick N-doped graphene (NG-NiFe@MoC 2 ) using one-step calcination of hybrid precursors composed of PVP-encapsulating NiFe-PBA and grafted Mo 6+ cations (Figure 15Ba).…”

Concurrent Photocatalytic Hydrogen Generation and Dye Degradation Using MIL‐125‐NH2 under Visible Light Irradiation

“…[21] For example, Yu et al developed an efficient electrocatalyst through an easy and scalable one-pot thermal treatment of bimetallic zeolitic imidazolate frameworks (ZIFs). [22] The formation, phase purity and morphology of the MOF-derived NPs were explored through PXRD, nitrogen isotherms and transmission electron microscopy (TEM) (see section S2). The PXRD patterns of the as-synthesised NiO, Ni2P, Co3O4, CoP, Fe2O3 and CuO NPs are in good agreement with the simulated and previously reported patterns (Figure 1).…”