Novel synthesis of nano-structured and porous gamma-Mo2N and gamma-Co0.25Mo1.75N materials have been successfully achieved. The methodologies involve (i) the reaction of metal ions with hydrazine and borohydride resulting MoO3 based procursors and (ii) their subsequent nitridation using NH3(g) at 700 degrees C. gamma-Mo2N and gamma-Co0.25Mo1.75N materials crystallize in fcc structure with lattice parameters, 'a' =4.193 (+/- 5) angstrom and 4.198 (+/- 2) angstrom, respectively. TEM and XRD studies confirm nano-crystalline nature of gamma-Mo2N and gamma-Co0.25Mo1.75N nitrides having TEM particle sizes of 5 and 12 nm and crystallite sizes of 6 and 11 nm, respectively. HRTEM study confirms lattice stacking and porous structures. BET surface area study indicates high and moderate surface areas for gamma-Mo2N and gamma-Co0.25Mo1.75N nitride materials, i.e. 53 and 12 m(2)/g, respectively which confirm mesoporous behavior. M vs H plots of gamma-Mo2N and gamma-Co0.25Mo1.75N materials show weak ferromagnetism having coercivities values of 2838 and 296 Oe, respectively. (C) 2016 Elsevier Ltd. All rights reserved.