钨掺杂NiFe-MOFs衍生的氮碳材料电催化析氧性能研究

Study on electrocatalytic oxygen evolution of nitrogen carbon materials derived from tungsten-doped NiFe MOFs

  • 摘要: 电解水制氢两步反应中的析氧反应有复杂的电子转移步骤,设计高效的析氧催化剂对于电解水制氢至关重要。基于多金属氧酸盐(POM)和金属有机骨架(MOFs)的多样催化活性,本文提出将Keggin型多金属氧酸盐(K6NaNi3(H2O)3PW10O39H2O)作钨源与MOFs结合,掺入氮后煅烧,在泡沫镍上生长掺钨的氮碳材料。经SEM、XRD和XPS表征显示,该材料是掺杂钨的珠链状镍铁双金属氮碳材料,拉曼光谱表示其具有较多缺陷结构促进催化作用。通过线性扫描伏安法(LSV)和Tafel曲线等电化学测试研究电催化析氧反应(OER)性能,结果表明,该材料在1.0 mol/L 的KOH碱性电解液中,电流密度为50 mA/cm2时其过电位为226 mV,塔菲尔斜率仅为78.64 mV/dec,工作10 h后性能几乎不变,表现出良好的催化活性和稳定性。

     

    Abstract: The oxygen evolution reaction in the two-step reaction of water electrolysis to hydrogen production involves complicated electron transfer steps. Designing an efficient oxygen evolution catalyst for hydrogen production by water electrolysis is essential. Based on the diverse catalytic activities of polyoxometalate (POM) and metal-organic frameworks (MOFs), this paper proposed to use Keggin-type polyoxometalate (K6NaNi3(H2O)3PW10O39H2O) as tungsten source and combined it with MOFs. After nitrogen doping and calcination, tungsten-doped nitrogen-carbon materials are grown on nickel foam. SEM, XRD and XPS characterizations showed that the doped material was a tungsten-doped polyoxometalate and nickel-ferroalloy bimetallic nitro-carbon material with bead chain and Raman spectra showed that such material had a high number of defect structures that promote catalytic effect. The electrocatalytic oxygen evolution (OER) performance was studied using linear sweep voltammetry (LSV) and the Tafel curve. The results showed that in 1.0 mol/L KOH alkaline electrolyte, the material’s overpotential was 226 mV when the current density was 50 mA/cm2. The Tafel slope was only 78.64 mV/dec, and the performance was almost unchanged after 10 hours of operation, showing good catalytic activity and stability.

     

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