| 초록 |
Highly active NixPy catalysts for HER are prepared using modified thermal decomposition method. In this process, nickel oxide (NiO) powder reduced to NixPy by phosphine gas (PH3) produced from sodium hypophosphite (NaH2PO2). Unlike conventional method, NiO is phosphidized from bi-located P source (NaH2PO2). Synthesized NixPy catalysts had multi-phase crystalline structure (Ni2P, Ni5P4 and NiP2) and the NixPy with higher P content exhibited the smaller crystallite size. (Ni2P＜50, Ni5P4~10, NiP2~2 nm). Consequently, Ni5P4 and NiP2 nanoparticles with higher HER activity are supported on micro-scaled Ni2P with better conductivity. The NixPy catalysts showed exceptionally higher HER activity in acidic media than single-phased Ni2P or Ni5P4. Therefore, modified phosphidation method and hierarchical structure of NixPy catalyst provide new instruction for designing excellent HER catalysts. |
