Synthesis of a Ni2P/Ni12P5 bi-phase nanocomposite for the efficient catalytic reduction of 4-nitrophenol based on the unique n–n heterojunction effects

Abstract

A novel heterostructure catalyst of Ni₂P/Ni₁₂P₅ has been fabricated through a simple solvothermal method by modifying the molar ratio of the initial raw materials. The products are characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM), nitrogen adsorption and X-ray photoelectron spectroscopy (XPS). It is found that the two phases, Ni₂P and Ni₁₂P₅, are interlaced with one another in the as-formed nanocomposite, resulting in more interfaces. The bi-phase catalyst exhibits a markedly enhanced catalytic activity in the reduction of 4-nitrophenol, as compared to that of single Ni₂P or Ni₁₂P₅. The enhanced catalytic activity can be attributed to the unique n–n series effects, which result in the increased ease of electron transfer over the Ni₂P/Ni₁₂P₅ bi-phase catalyst.