Crystalline Phase and Size-controlled Synthesis of Nickel Phosphide Nanocrystals

Abstract

Nanostructured nickel phosphides were synthesized via a thermal decomposition approach. The effect of synthetic conditions such as P:Ni precursor mole ratio, reaction temperature, reaction time, reductant oleylamine quantity and species of additive on the crystalline phase and size of the as-synthesized nickel phosphides was discussed systematically. The results show that lower P:Ni precursor mole ratio, higher reaction temperature, shorter reaction time and the addition of oleic acid were beneficial to form Ni12P5 phase with large size. In contrast, higher P:Ni precursor mole ratio, lower reaction temperature, longer reaction time and the addition of octadecene were beneficial to form Ni2P phase with small size. The variety of oleylamine quantity cannot realize the phase-controlled synthesis, but the size can be controlled. These synthetic method also can be used to synthesize others transition metal phosphides.