Institute for Clean Energy & Advanced Materials, Faculty of Materials & Energy, Southwest University, Chongqing, 400715, P.R. China.
Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Chongqing, 400715, P.R. China.
ChemSusChem. 2017 Mar 9;10(5):1014-1021. doi: 10.1002/cssc.201601761. Epub 2017 Jan 31.
A highly active, durable, and low-cost hydrogen evolution reaction (HER) catalyst is desirable for energy storage through water splitting but its fabrication presents great challenges. Herein, mediated by dynamically self-assembled graphene quantum dots (GQDs), small, uniform, high-density, and well-dispersed CoP nanoparticles were grown in situ on pristine graphene for the first time. This hybrid nanostructure was then employed as HER electrocatalyst, showing an onset potential of 7 mV, an overpotential of 91.3 mV to achieve 10 mA cm , a Tafel slope of 42.6 mV dec , and an exchange current density of 0.1225 mA cm , all of which compare favorably to those of most reported non-noble-metal catalysts. The developed catalyst also exhibits excellent durability with negligible current loss after 2000 cyclic voltammetry cycles (+0.01 to -0.17 V vs. RHE) or 34 h of chronoamperometric measurement at an overpotential of 91.3 mV. This work not only develops a new strategy for the fabrication of high-performance and inexpensive electrocatalysts for HER but also provides scientific insight into the mechanism of the dynamically self-assembled GQDsmediated synthesis process.
一种高效、稳定、低成本的析氢反应（HER）催化剂对于通过水分解进行储能是理想的，但它的制备却带来了巨大的挑战。在此，首次通过动态自组装的石墨烯量子点（GQDs）介导，在原始石墨烯上原位生长出小、均匀、高密度和良好分散的 CoP 纳米粒子。然后，将这种混合纳米结构用作 HER 电催化剂，表现出 7 mV 的起始电位、91.3 mV 的过电位即可达到 10 mA cm-2、42.6 mV dec-1 的塔菲尔斜率和 0.1225 mA cm-2 的交换电流密度，所有这些都优于大多数报道的非贵金属催化剂。所开发的催化剂还表现出优异的耐久性，在 2000 次循环伏安（+0.01 至-0.17 V 与 RHE 相比）或在 91.3 mV 的过电位下进行 34 小时计时电流测量后，电流损失可忽略不计。这项工作不仅为制备高性能、低成本的 HER 电催化剂开发了一种新策略，而且为动态自组装 GQDs 介导的合成过程的机制提供了科学见解。
