State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University , Changsha, 410082, P.R. China.
ACS Appl Mater Interfaces. 2017 Feb 22;9(7):5982-5991. doi: 10.1021/acsami.6b14127. Epub 2017 Feb 8.
Double metal phosphide (NiCoP) with hollow quasi-polyhedron structure was prepared by acidic etching and precipitation of ZIF-67 polyhedra and further phosphorization treatment with NaHPO. The morphology and microstructure of NiCoP quasi-polyhedron and its precursors were investigated by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and a micropore and chemisorption analyzer. Electrocatalytic properties were examined by typical electrochemical methods, such as linear sweep voltammetry, cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy in 1.0 M KOH aqueous solution. Results reveal that, compared with CoP hollow polyhedra, NiCoP hollow quasi-polyhedra exhibit better electrochemical properties for hydrogen evolution with a low onset overpotential of 74 mV and a small Tafel slope of 42 mV dec. When the current density is 10 mA cm, the corresponding overpotential is merely 124 mV, and 93% of its electrocatalytic activity can be maintained for 12 h. This indicates that NiCoP with hollow quasi-polyhedron structure, bimetallic merit, and low cost may be a good candidate as electrocatalyst in the practical application of hydrogen evolution.
具有中空拟多面体结构的双金属磷化物（NiCoP）是通过 ZIF-67 多面体的酸性蚀刻和沉淀以及进一步用 NaHPO 进行磷化处理制备的。采用扫描电子显微镜、透射电子显微镜、X 射线衍射和微孔和化学吸附分析仪研究了 NiCoP 拟多面体及其前体的形貌和微观结构。在 1.0 M KOH 水溶液中，通过典型的电化学方法，如线性扫描伏安法、循环伏安法、计时电流法和电化学阻抗谱对电催化性能进行了测试。结果表明，与 CoP 中空多面体相比，NiCoP 中空拟多面体具有更好的析氢电化学性能，其起始过电位低至 74 mV，塔菲尔斜率小至 42 mV dec。当电流密度为 10 mA cm 时，对应的过电位仅为 124 mV，其电催化活性的 93%可以在 12 h 内保持。这表明具有中空拟多面体结构、双金属优点和低成本的 NiCoP 可能是析氢实际应用中一种良好的电催化剂候选材料。
