Trace Level Co–N Doped Graphite Foams as High-Performance Self-Standing Electrocatalytic Electrodes for Hydrogen and Oxygen Evolution

Abstract

The development of eco-friendly electrocatalysts with high performance and low cost for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is significant for renewable energy storage. Here, trace level (0.11−0.18 wt %) Co−N doped graphite foam (Co−N/GF) was reported to work as a bifunctional high-performance and self-standing electrode for both HER and OER in alkaline electrolyte. The catalytic activities of Co−N/GFs with different annealing temperatures (600, 700, 800, 900, and 1000 °C) were carefully studied. Among them, Co−N/GF-900 exhibited the best HER activity and Co−N/GF-700 showed the best OER activity, achieving the current density of 10 mA cm −2 at low overpotentials of 165 and 313 mV, respectively. In addition, both of these electrodes exhibited long-term durability. Co−N/GF electrodes were further constructed as a catalytic cathode and anode couple (Co−N/GF-900∥Co−N/GF-700) for overall water splitting, exhibiting a low cell voltage of 1.68 V and good long-term stability. Our work reveals that introducing a trace level of Co−N into graphite foam can significantly enhance its electrocatalytic activity and stability for both HER and OER.

Boosting the activity of Prussian-blue analogue as efficient electrocatalyst for water and urea oxidation

“…As displayed in Fig. 4a,c, the dominant peaks located at 781.4 and 797.6 eV were ascribed to Co 3+ 2p 3/2 and 2p 1/2 , respectively, and the binding energy at 782.6 eV was assigned to Co 2+ 2p 3/2 24,39,42,50 . It was obvious that in CFHC the XPS peaks at 781.4 eV for Co 3+ were enhanced while the peak corresponding to Co 2+ at 782.6 eV was decreased (Fig.…”

“…Therefore, it is appealing but highly challenging to design and construct earth-abundant and low-cost electrocatalysts for OER and UOR. Up to now, various noble-metal-free catalysts have been developed, such as metal oxides 16,17 , metal hydroxides 18–20 , metal chalcogenides 21,22 , metal phosphides 23 , metal nitrides 24 , and metal carbides 25 , etc. However, the performance of these reported materials as a bifunctional electrocatalyst both for OER and UOR are far from the industrial utilization.…”

Carbon quantum dots enhanced the activity for the hydrogen evolution reaction in ruthenium-based electrocatalysts

“…Benefiting from excellent tuneable surface physical chemical properties, thermal stability and corrosion resistance against acid and alkali, carbon nanomaterials have been widely applied in constructing carbon composite electrocatalysts. [21][22][23] Due to the strong metal-support interactions, support materials usually play a vital role in optimising the local electronic and geometric structures of metal sites. 24,25 In the development of support materials, the tuning and stabilising effect over the catalytic sites should be considered.…”

N, S and Transition-Metal Co-Doped Graphene Nanocomposites as High-Performance Catalyst for Glucose Oxidation in a Direct Glucose Alkaline Fuel Cell

“…In particular, heteroatom doping was effective on the increase of active sites and regulation of electron distribution [ 18 , 19 , 20 , 21 , 22 ]. It has been demonstrated that co-doping multi elements with different electronegativity can remarkably improve the performance of graphene due to the positive synergistic effect of heteroatoms [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. Ci et al [ 35 ] simultaneously doped graphene with nitrogen and loaded cobalt to obtain Co/NG catalyst by heat treatment.…”