Cobalt Boron Imidazolate Framework Derived Cobalt Nanoparticles Encapsulated in B/N Codoped Nanocarbon as Efficient Bifunctional Electrocatalysts for Overall Water Splitting

Abstract

The development of efficient and low-cost bifunctional electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is highly desirable for electrochemical energy conversion. Herein, this study puts forward a new Co decorated N,B-codoped interconnected graphitic carbon and carbon nanotube materials (Co/NBC) synthesized by direct carbonization of a cobalt-based boron imidazolate framework. It is demonstrated that the carbonization temperature can tune the surface structure and component of the resultant materials and optimize the electrochemically active surface area to expose more accessible active sites, effectively boosting the electrocatalytic activity. As a result, the optimized Co/NBC shows superior bifunctional catalytic activity and stability toward OER and HER in 1.0 m KOH solution. Furthermore, the catalyst can serve as both the anode and cathode for water splitting to achieve a current density of 10 mA cm −2 at a cell voltage of 1.68 V. Experimental results and theoretical calculations indicate that the excellent activity of Co/NBC catalyst benefits from the synergistic effect of partial oxidation of metallic cobalt, conductive N,B-codoped graphitic carbon and carbon nanotube, and the coupled interactions among these components. This work opens a promising avenue toward the exploration of boron imidazolate frameworks as efficient heteroatom-doped catalysts for electrocatalysis.

Gold Doping in a Layered Co‐Ni Hydroxide System via Galvanic Replacement for Overall Electrochemical Water Splitting

“…Although much progress has been made in fabricating materials that are active for either the OER or HER, fewer materials that are bifunctional and active for both reactions have been developed . There have been many reports on the use of metal sulfides, phosphides, and selenides, which are known electrocatalysts for the HER, to be also active for the OER.…”

An efficient bio‐inspired catalytic tool for hydrogen release at room temperature from a stable borohydride solution

“…In the open literature, many studies propose interesting highly efficient catalysts. [14][15][16] However, generally these catalysts are under powder form and are not compatible with process intensification (eg, continuous process). The main drawbacks with catalytic powders include high pressure drop, low catalyst recyclability and process engineering.…”

Noble metal-free two dimensional carbon-based electrocatalysts for water splitting

“…The heteroatoms of B, S, N, P, F, and O hold great potential to alter the intrinsic properties of graphene based materials and enable them to adsorb reactant species on their surface without disturbing their electrical conductivities, which shows the availability of foundation for unusual catalytic performances [65][66][67][68]. Furthermore, it has (4) [118] CoO/NC Pyrolysis 1.0 M KOH 1.55 [151] CoP/NC Annealing 1.0 M KOH 1.73 [147] CoP/rGO Annealing/phosphoration 1.0 M KOH 1.56 [138] CoP/rGO Pyrolysis 1.0 M KOH 0.47 [145] Co-BNC Carbonization 1.0 M KOH 1.68 [180] CoP/NPMG Carbonization 1.0 M KOH 1.60 [149] NiP/C Electrodeposition/phosphoration 1.0 M KOH 1.63 [146] VCN@Fe 4 N/FeOOH Annealing 0.1 M KOH 1.60 [153] NiFe-LDH NS@DG Suspension 1.0 M KOH 1.50 [156] been noted that the modification of graphene via high electronegative heteroatom (e.g., N, F, and O) doping can easily modulate the electronic structures by activating the adjacent carbon atoms in the graphene, leading to increase catalytic sites, which ultimately boosts up the electrochemical activities for water splitting [69]. In addition, the co-doping with higher and lower electronegative heteroatoms can also provide a synergistic effect between heteroatoms with a distinctive electronic structure and consequently enhance the activity of heteroatom-doped graphene-based electrocatalysts [70].…”