This work shows a novel environmentally benign microwave (MW) assisted method for the fabrication of Ni-0 nanoparticles. The objective was the development of a rapid and self-sustainable solvothermal method, starting from concentrated nickel hydroxide suspensions. Suspensions of nickel hydroxide (Ni(OH)(2)) in ethylene glycol (EG) were converted to Ni-0 nanoparticles at 260 degrees C without the need for any supplementary catalysts. The MW irradiation initiated the dissociation of nickel hydroxide to Ni2+ and mobile OH- ions thus triggering the partial catalytic oxidation of EG. As a consequence, two electrons became available to reduce Ni2+ to metallic Ni-0 nanoparticles. This process is self-sustainable as the Ni-0 nanoparticles then become the catalytic domains for further oxidation of EG and resulting in a faster kinetics for the complete reduction of nickel hydroxide within 60 min. Interestingly, the MW-assisted process was also effective in multiple recycling of EG, forming Ni-0 nanoparticles after each reduction cycle. This process dispenses the need for using a high amount of solvents as required in conventional solvothermal methods, and greatly reduces solvent waste generation. In addition, this novel process led to almost 100% conversion of highly concentrated suspensions (1.2 M Ni(OH)(2)) to Ni-0 nanoparticles, which is very attractive for a large scale production. (C) 2013 Elsevier B.V. All rights reserved.