4. Concluding remarks
We have successfully synthesized NiSe nanoparticles using ball milling and solution phase methods. To the best of our knowledge, NiSe nanoparticle is the first material obtained by ball milling used for the reduction of PNA–PPD and PNP–PAP. The particle size of the materials was controlled by changing the different size of tungsten carbide balls in the ball milling method and the morphology has been controlled by the use of surfactants in the polyol method. Our various controlled synthesis and studies on the catalytic activity towards the reduction of PNA and PNP suggest that particle size, morphology and the presence of surfactant plays crucial role in the catalytic activity of the nanoparticles. The material synthesized by ball milling showed slightly better activity compared to the materials synthesized by solution method although the role of the surfactants could play a crucial role. Our catalysts also showed good activity, which is comparable to the best reported noble metals and related compounds. Since there is no need of any chemical reagents and synthesis duration is short, ball milling method can be considered as a facile and efficient method for producing nanomaterials in large amounts as catalysts for various reactions. Our study can motivate the development of various low cost compounds not only for reduction but also for several other industrially based catalytic reactions.