Jiangsu Collaborative Innovation Centre of Biomedical Functional Materials, Jiangsu Key Laboratory of New Power Batteries, School of Chemistry and Materials Science, Nanjing Normal University , Nanjing 210023, China.
ACS Appl Mater Interfaces. 2017 May 24;9(20):16977-16985. doi: 10.1021/acsami.7b01096. Epub 2017 May 10.
The development of highly efficient and low-cost oxygen evolution electrocatalysts is extremely imperative for the new energy technology. Transition metal carbides have been investigated as remarkable hydrogen evolution reaction (HER) electrocatalysts but undesired oxygen evolution reaction (OER) electrocatalysts and need further study. Here, a cobalt-molybdenum-based bimetallic carbide coated by N-doped porous carbon and anchored on N-doped reduced graphene oxide film (CoMoC/NCRGO) is synthesized by directly carbonizing the Co-doped polyoxometalate/conductive polymer/graphene oxide (Co-PCG) precursors. The precise control of the Co/Mo molar ratio in the Co-PCG precursor is of critical importance to synthesize pure phase bimetallic carbide of CoMoC. As the highly active and robust OER electrocatalyst, the CoMoC/NCRGO composite exhibits excellent activity in alkaline solution, affording a low overpotential of 260 mV versus RHE at 10 mA cm, a small Tafel slope of 50 mV dec, as well as long-term stability. The superior OER performances are strongly associated with the active CoMoC particles, polypyrrole (PPy)-derived N-doped porous carbon, and the conductive RGO films. Remarkably, it is the first evidence that the bimetallic carbides were used as the OER catalysts with such high OER activity.
开发高效、低成本的析氧电催化剂对于新能源技术来说是极其必要的。过渡金属碳化物已被研究为出色的析氢反应 (HER) 电催化剂，但作为不理想的氧析出反应 (OER) 电催化剂仍需要进一步研究。在此，通过直接碳化 Co 掺杂的多金属氧酸盐/导电聚合物/氧化石墨烯 (Co-PCG) 前体，合成了一种由 N 掺杂多孔碳包覆并锚定在 N 掺杂还原氧化石墨烯薄膜上的钴钼基双金属碳化物 (CoMoC/NCRGO)。Co-PCG 前体中 Co/Mo 摩尔比的精确控制对于合成纯相双金属碳化物 CoMoC 至关重要。作为高活性和强稳定性的 OER 电催化剂，CoMoC/NCRGO 复合材料在碱性溶液中表现出优异的活性，在 10 mA cm 时提供 260 mV 相对于 RHE 的低过电势、50 mV dec 的小塔菲尔斜率以及长期稳定性。优异的 OER 性能与活性 CoMoC 颗粒、吡咯 (PPy) 衍生的 N 掺杂多孔碳和导电 RGO 薄膜密切相关。值得注意的是，这是首次证明双金属碳化物可用作具有如此高 OER 活性的 OER 催化剂。
