碳纳米管载钴基纳米材料的制备:一种优异的电催化析氢活性材料

Preparation of CoNiP nanoparticles supported on nitrogen-doped carbon nanotubes as high performance electrocatalysts for the hydrogen evolution reaction

在高效过渡金属磷化物催化剂中,钴镍磷(CoNiP)以其优异的析氢催化活性,被认为是最有可能在将来替代贵重金属铂的一类催化剂。采用一种简单的工业浸渍法和两步煅烧法制备了在氮掺杂碳纳米管上(NCNTs)均匀分散的CoNiP纳米颗粒,获得了具有高效析氢活性的催化材料(CoNiP/NCNTs),该材料具有较低的过电位和良好的析氢稳定性等优点。在磷化物的合成过程中,磷源加入的量是影响其性能至关重要的因素。实验通过改变磷化过程中加入次磷酸钠的量考察了磷源含量对材料催化性能的影响。经过优化后的CoNiP/NCNTs纳米材料,在0.5 mol/L的硫酸溶液中具有44 mV的初始过电位,并且在电流密度为10 mA cm-2的时候,过电位仅为75 mV。经过24 h的稳定性测试,电位仅下降6 mV。因此,实验制备的催化材料具有优异的析氢催化性能,在工业产氢领域具有很好的应用潜力。

CoNiP nanoparticles dispersed on nitrogen-doped carbon nanotubes(NCNTs)as electro catalysts for the hydrogen evolution reaction were prepared by impregnating the NCNTs with a solution containing Ni(NO3)2·6 H2O and Co(NO3)2·6 H2O,followed by calcination at 500 for 2 h and phosphorization at 350 for 2 h in a furnace with a crucible of sodium hypophosphite upstream of the CoNi02/NCNT that served as the phosphorization agent.Results indicated that the CoNiP/NCNT catalysts had the advantages of low overpotential and high durability.The sodium hypophosphite content was a crucial factor affecting the performance of the catalysts.The optimized CoNiP/NCNT catalyst with an appropriate content of the phosphorization agent(0.2 g sodium hypophosphite/0.02 g CoNiO2/NCNT)exhibited the best performance with an onset-overpotential of 44 mV and an overpotential of75 mV at a current density of 10 mA cm-2 in 0.5 M H2 SO4.After the chronopotentiometry measurement for 24 h,the overpotential showed a decrease of only 6 mV,indicating its excellent durability.