Self‐Assembled CoFe Nanoparticle‐Embedded Carbon Nanowires as Efficient Nonprecious Catalyst for Overall Water Splitting

Abstract

At present, it is still challenging to develop nonprecious transition metal‐based electrocatalysts with a high efficiency and stability for overall water splitting. To address such issues, for the first time, a novel nonprecious hybrid electrocatalyst—a self‐assembled CoFe nanoparticle‐embedded porous carbon nanowires (CoFe@CNWs)—is designed and synthesized via a facile hydrothermal reaction and subsequent annealing process. This hybrid electrocatalyst demonstrates an outstanding performance for oxygen evolution reaction (OER) with a very small Tafel slope of 63 mV dec−1 and an ultralow onset overpotential of 170 mV; particularly, when the hybrid is used for overall water splitting, the cell voltage is as low as 1.69 V at a current density of 10 mA cm−2. The excellent electrocatalytic performance of CoFe@CNWs is attributed to its unique porous nanoarchitecture, constructed by ultrasmall conductive CoFe nanoparticles homogenously embedded in highly conductive CNWs, which would not only guarantee abundant catalytic sites and structural stability but also facilitate electron transportation, resulting in a significant improvement in the electrocatalytic performance. This work provides a strategy to rationally design and synthesize a nanostructured transition metal‐based hybrid to be used as a highly effective and stable nonprecious electrocatalyst for overall water splitting.

CoFe‐P/Ti3C2Tx Nanosheets as Efficient Electrocatalyst for the Oxygen Evolution Reaction

“…Even so, the electrocatalytic performance of transition metal phosphides is still far from satisfactory due to their intrinsically poor conductivity. [21][22] In recent years, a large number of highly conductive materials (carbon nanotubes, [23] carbon nanowires, [24] rGo, [25] etc.) have been used as excellent hybrid agents to boost the overall electrical conductivity.…”

Bimetallic CoNi Alloy Nanoparticles Embedded in Pomegranate-like Nitrogen-Doped Carbon Spheres for Electrocatalytic Oxygen Reduction and Evolution

“…24 Wu et al display that Co−N−C species produced by Co 3 O 4 nanoparticles cooperating with nitrogen atoms act as a bond bridge to link the Co 3 O 4 nanoparticles and N-doped carbon lattice, introducing the extra active sites for the OER. 25 Among the many, transition metal alloys, such as CoFe, 26,27 CoNi, 28 and MnCo, 29 have been attracting much attention due to the superior activity of the individual component and corresponding oxide. Particularly, bimetallic CoNi alloy is a potential candidate among various bimetallic alloys because of its earth abundance instinct and are more conductive and stable than Fe as well as its cost effectiveness.…”

“…Wu et al display that Co–N–C species produced by Co 3 O 4 nanoparticles cooperating with nitrogen atoms act as a bond bridge to link the Co 3 O 4 nanoparticles and N-doped carbon lattice, introducing the extra active sites for the OER . Among the many, transition metal alloys, such as CoFe, , CoNi, and MnCo, have been attracting much attention due to the superior activity of the individual component and corresponding oxide. Particularly, bimetallic CoNi alloy is a potential candidate among various bimetallic alloys because of its earth abundance instinct and are more conductive and stable than Fe as well as its cost effectiveness. , Due to the synergistic effect, CoNi alloy not only provides rich valence state changes with a strong electron coupling but also intrigues the surface properties alternation and the intrinsic polarity shift in the process of oxygen reactions. ,, Bifunctional electrocatalysts combined with bimetallic CoNi alloy and doped carbon enables the kinetics promotion for both OER and ORR.…”