N-Doped Graphene-Decorated NiCo Alloy Coupled with Mesoporous NiCoMoO Nano-sheet Heterojunction for Enhanced Water Electrolysis Activity at High Current Density

Abstract

Developing highly effective and stable non-noble metal-based bifunctional catalyst working at high current density is an urgent issue for water electrolysis (WE). Herein, we prepare the N-doped graphene-decorated NiCo alloy coupled with mesoporous NiCoMoO nano-sheet grown on 3D nickel foam (NiCo@C-NiCoMoO/NF) for water splitting. NiCo@C-NiCoMoO/NF exhibits outstanding activity with low overpotentials for hydrogen and oxygen evolution reaction (HER: 39/266 mV; OER: 260/390 mV) at ± 10 and ± 1000 mA cm−2. More importantly, in 6.0 M KOH solution at 60 °C for WE, it only requires 1.90 V to reach 1000 mA cm−2 and shows excellent stability for 43 h, exhibiting the potential for actual application. The good performance can be assigned to N-doped graphene-decorated NiCo alloy and mesoporous NiCoMoO nano-sheet, which not only increase the intrinsic activity and expose abundant catalytic activity sites, but also enhance its chemical and mechanical stability. This work thus could provide a promising material for industrial hydrogen production.

Constructing RuCoOx/NC Nanosheets with Low Crystallinity within ZIF‐9 as Bifunctional Catalysts for Highly Efficient Overall Water Splitting

“…As shown in Figure 7a, RuCoO x /NC‐350 displayed typical IV isotherm characteristic of mesoporous material. The presence of mesopores in material promotes the diffusion of reactants and products, thus accelerating the process of electrocatalytic reaction [39] . The specific surface area of RuCoO x /NC‐350 was calculated to be 60.5 m 2 g −1 based on the BET method, the large specific surface area is conducive to the dispersion of metal active sites and the contact between electrolyte and active sites.…”

Facile Fabrication of Robust Hydrogen Evolution Electrodes under High Current Densities via Pt@Cu Interactions

“…[14] Moreover, NiCo@C-NiCoMo/NF was developed by Yin's group, the chronoamperometry measurement was under −1000 mA cm −2 , indicating its remarkable stability. [15] On the other side, the robust interaction between electrocatalysts and substrates ensures efficient usage and reduces the loading of active materials.…”

In‐situ Surface‐selective Removal of Al Element from NiFeAl Ternary Nanowires for Large‐current Oxygen Evolution Reaction

“…For the oxygen evolution reaction, it is significant to obtain a high current density of more than 100 mA ⋅ cm −2 , and the performance of NiFeAl‐NW/NF is better than that of most reported non‐noble metal based OER catalysts. Table S1 compares the OER activity of NiFeAl‐NW/NF with that of many non‐noble metal based catalysts reported recently, which shows that the OER activity of NiFeAl‐NW/NF is better than that of most non‐noble metal based catalysts at the current density of 1000 mA ⋅ cm −2 , such as NiCo@C‐NiCoMoO/NF (390 mV), [24] NiCoV‐LTH (373 mV), [25] Porous Co‐P (380 mV) [26] and 2D Ni‐MOF‐250 (410 mV) [27] …”