高效Mo-Ni_(5)P_(4)双功能电催化剂的制备及其电解水性能研究

Preparation and Electrolytic Water Performance of an Economically Efficient Mo-Ni_(5)P_(4)Bifunctional Electrocatalyst

电催化制氢通过析氢反应(HER)和析氧反应(OER)同时产生氢气(H 2)和氧气(O 2),是一种高效且环境友好的产氢方式。但现阶段商业化的高效催化剂价格昂贵且储量较少,限制了电解水技术的大规模应用。因此,开发低成本、高稳定和环境友好的高效电催化剂,特别是基于非贵金属材料的磷化物电催化剂,成为近期研究热点。本研究通过水热和相对较低的磷化温度成功制备出了具有镂空纳米花结构的Mo掺杂Ni_(5)P_(4)催化剂。通过X射线衍射(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)对Mo-Ni_(5)P_(4)催化剂进行了表征,并研究了Mo-Ni_(5)P_(4)材料的电化学性能。研究发现,所合成的催化剂凭借掺杂对电子结构的改变,以及多孔纳米片的大表面积优势,提高了HER水解离步骤的速率。在碱性电解液中,Mo负载下的Ni_(5)P_(4)仅需116 mV的析氢过电位就可实现10 mA·cm^(-2)的电流密度,同时析氧过电位只需255 mV。在双电极配置中仅需1.608 V的电池电压,持续测试27 h后,催化剂仍显示出良好的稳定性。

Electrocatalytic hydrogen production,to produce hydrogen(H_(2))and oxygen(O_(2))at the same time through hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),which is considered as an efficient and environmentally friendly way to produce hydrogen.However,the high-efficiency catalysts for commercialization are expensive and have limited reserves,which limit the large-scale application of electrolytic water technology.Therefore,the development of efficient electrocatalysts with low cost,high stability and environmental friendliness,especially phosphides based on non-precious metal materials,is very challenging and much desired.Here,Mo-doped Ni_(5)P_(4)catalysts with hollow nanoflower structure were successfully prepared by hydrothermal and relatively low phosphorylation temperature.The microstructure of Mo-Ni_(5)P_(4)catalysts was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM)and transmission electron microscopy(TEM),and the electrochemical properties of Mo-Ni_(5)P_(4)materials were investigated.The results show that,catalysts synthesized in this work promote the rate of the HER water dissociation step,taking advantage of the Mo and Ni_(5)P_(4)hollow structures change and the large surface area of the porous nanosheets.In alkaline electrolytes,Ni_(5)P_(4)under Mo loading requires only 116 mV of hydrogen evolution overpotential to achieve a current density of 10 mA·cm-2,while only 255 mV of oxygen evolution overpotential is required.In a two-electrode configuration,a battery voltage of only 1.608 V is required.The catalyst still shows good stability after 27 h of continuous testing.