铱钴纳米纤维作为一种高效稳定的双功能电催化剂用于高性能水裂解

Iridium-incorporated cobalt nanofibers as efficient and robust bifunctional catalysts for high-performance water electrolysis

本文通过静电纺丝-煅烧-原位氢还原-置换工艺制备了嵌入铱的钴纳米纤维(Co-Ir-600).得益于独特的一维纳米纤维异质结构给予的快速电子传输和传质过程以及Ir和Co两组分之间的协同作用,Co-Ir催化剂在碱性电解质中达到10 mA cm-2电流密度仅需169 mV的极低过电位,表现出优异的析氧电催化活性.此外,该催化剂还具有良好的析氢反应性能.我们构建了一种将Co-Ir-600纳米纤维催化剂同时作为阳极和阴极的碱性电解槽,其只需要1.51 V的低电池电压即可达到10 mA cm-2的电流密度且耐用性好,性质明显优于参照的Pt/C||IrO_(2)以及许多已报道的水电解槽.本研究为制备经济高效的金属基水裂解电催化剂提供了一种通用有效的方法.

Iridium (Ir)-incorporated cobalt (Co) nanofibers (Co-Ir-600) are fabricated via an electrospinning-calcination-in situ H_(2)reduction-galvanic replacement process Benefitting from the unique one-dimensional nanofibrous heterostructure that allows rapid electron/mass transfer as well as the synergy between Ir and Co components,the Co-Ir catalyst shows a remarkable electrocatalytic activity for oxygen evolution reaction (OER) with an extremely low overpotentia of 169 mV at 10 mA cm-2in an alkaline electrolyte.Furthermore,the catalyst also presents a high hydrogen evolution reaction (HER) performance.Therefore,an alkaline electrolyzer is constructed with the Co-Ir-600 nanofibrous catalyst as both the anode and cathode electrodes,and only a small cel voltage of 1.51 V is needed to achieve 10 mA cm-2with outstanding durability.This performance is superior to that of benchmark Pt/C||IrO_(2)electrodes and many other reported water electrolysis cells.This study supplies a general and efficient way to prepare cost-effective and high-performance metal-based overall water splitting electrocatalysts.