Self-Standing CoP Nanosheets Array: A Three-Dimensional Bifunctional Catalyst Electrode for Overall Water Splitting in both Neutral and Alkaline Media
Self-Standing CoP Nanosheets Array: A Three-Dimensional Bifunctional Catalyst Electrode for Overall Water Splitting in both Neutral and Alkaline Media
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DOI：
10.1002/celc.201700392
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发表时间：
2017-08-01
期刊：
影响因子：
4
通讯作者：
Chen, Liang
中科院分区：
文献类型：
--
作者：
Liu, Tingting;Xie, Lisi;Chen, Liang
在中性和碱性条件下，为析氢反应（HER）和析氧反应（OER）开发高效的非贵金属电催化剂是一项极具吸引力但仍面临巨大挑战的研究课题。本文报道了由α - co (OH)(2) NA/CC衍生而成的碳布上CoP纳米片阵列（CoP NA/CC）在中性和碱性介质中表现为具有高活性和耐久性的三维双功能水分解催化剂电极。这样的CoP NA/CC需要145和52 mV的过电位才能分别在1.0 M磷酸盐缓冲溶液（PBS）和1.0 M KOH中为HER提供10 mA cm(-2)，其活性远优于α - co (OH)(2) NA/CC。根据密度泛函理论计算，这可归因于CoP比α - co (OH)(2)具有更多的热中性氢吸附自由能。该电极在α - co (OH)(2) NA/CC上也显示出优越的OER活性，并且在中性和碱性pH下分别需要536和300 mV的过电位来驱动10 mAcm（-2）。以CoP NA/CC为正极和负极的双电极水电解槽在1.0 M PBS条件下，电池电压为1.60 V时的解水电流为2 mAcm(-2)，在碱性条件下，10 mAcm（-2）的解水电流为1.65 V，稳定性极佳。
It is highly attractive, but still remains a huge challenge, to develop efficient non-noble-metal electrocatalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) under neutral and alkaline conditions. In this paper, we report that CoP nanosheet arrays on carbon cloth (CoP NA/CC), derived from alpha-Co(OH)(2) NA/CC, behaves as a three-dimensional bifunctional water-splitting catalyst electrode with high activity and durability in neutral and alkaline media. Such CoP NA/CC demands overpotentials of 145 and 52 mV to afford 10 mA cm(-2) for the HER in 1.0 M phosphate buffer solution (PBS) and 1.0 M KOH, respectively, with much superior activity to alpha-Co(OH)(2) NA/CC. It can be attributed to the more thermo-neutral hydrogen adsorption free energy for CoP than alpha-Co(OH)(2), according to density functional theory calculations. This electrode also demonstrates superior OER activity over alpha-Co(OH)(2) NA/CC and needs overpotentials of only 536 and 300 mV to drive 10 mAcm(-2) at neutral and alkaline pH, respectively. The two-electrode water electrolyzer using CoP NA/CC as both the cathode and anode shows a 2 mAcm(-2) water-splitting current at a cell voltage of 1.60 V in 1.0 M PBS and needs 1.65 V for 10 mAcm(-2) under alkaline condition with excellent stability.