高电导率银纳米线@聚吡咯@CoNi气凝胶的制备及其电催化析氧性能

Synthesis and electrocatalytic oxygen evolution performances of high conductivity silver nanowire@polypyrrole@CoNi alloy aerogels

  • 摘要: 针对传统贵金属析氧反应(OER)电催化剂的电导率较低、催化活性较差、成本高等问题,开发高效耐久、低成本且具有高暴露活性表面和优良导电性的电催化剂已迫在眉睫。通过冷冻干燥法合成银纳米线@聚吡咯(AgNWs@PPy)气凝胶,然后使用溶剂热法在AgNWs@PPy气凝胶骨架表面生长纳米CoNi合金,获得了OER电催化性能良好的AgNWs@PPy@CoNi气凝胶。结果表明,随着Co2+、Ni2+浓度的增加,AgNWs@PPy@CoNi气凝胶的催化性能先增强后减弱,当Co2+、Ni2+浓度为0.0175 mol/L制备的AgNWs@PPy@CoNi气凝胶在电流密度10 mA·cm−2时,过电位为346 mV,Tafel斜率为86.25 mV·dec−1,在恒定电压下经过10 h的稳定性测试,电流保持率达93.9%,具有良好的稳定性。三维独立型AgNWs@PPy气凝胶提供优良的导电性,CoNi合金提供丰富的活性位点,二者的共同作用表现出优异的OER催化性能,将有望替代贵金属催化剂而成为新型的OER催化材料。

     

    Abstract: Given the low conductivity, poor catalytic activity, and high cost of traditional noble metal-oxygen evolution reaction (OER) electrocatalysts, it is urgent to develop electrocatalysts with high efficiency, durability, low cost, high exposed active surface, and excellent electrical conductivity. The Silver nanowire@Polypyrrole (AgNWs@PPy) aerogels were synthesized by freeze-drying method, and then nano-CoNi alloy was grown on the surface of AgNWs@PPy aerogels framework by solvothermal method, and AgNWs@PPy@CoNi aerogels with good OER electrocatalytic performance was obtained. The results show that the catalytic performance of AgNWs@PPy@CoNi aerogels first increase and then weaken with the increase of Co2+ and Ni2+ concentrations. When the Co2+ and Ni2+ concentrations are 0.0175 mol/L, the AgNWs@PPy@CoNi aerogels exhibite high current density. At 10 mA·cm−2, the overpotential is 346 mV, and the Tafel slope is 86.25 mV·dec−1. After a 10-hour stability test under a constant voltage, the current retention rate reaches 93.9%, which has good stability. The three-dimensional independent AgNWs@PPy aerogels provide excellent electrical conductivity, and the CoNi alloy provides abundant active sites. The combined effect of them shows excellent OER catalytic performance, which is expected to replace precious metal catalysts and become a new type of OER catalytic material.

     

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