Phosphorus role on the enhancement in catalytic activity of magnetic Ni-P alloy

The Ni-P alloy with different composition of phosphorus was synthesised using borohydride assisted chemical reduction method. The compositional analysis of the alloy shows predominant reduction of nickel than phosphorus in all the alloy samples. The surface morphology of the alloy changes from flakes like nature to foam like nature with increasing phosphorus content. The XRD studies shows formation of fcc nickel phase in all the annealed alloy samples. The phase transition of as-synthesised Ni-P alloy was observed using DSC. The room temperature magnetic property of Ni-P alloy was studied using VSM showing soft ferromagnetic nature in annealed samples. The saturation magnetization value of the alloy decreases periodically with increasing phosphorus content. The Ni-P alloy shows excellent catalytic activity towards the reduction of 4-nitrophenol to 4-aminophenol with maximum rate constant of 0.27 min−1. The stability of most active sample is calculated, which shows stability of up to 4 cycle is found with same rate constant.