Facile mechanical milling synthesis of NiCr^sub 2^O^sub 4^ using novel organometallic precursors and investigation of its photocatalytic activity

Herein, NiCr2O4 nanostructures were successfully prepared via a facile and solvent-less ball milling method using new set of organometallic starting reagents including Ni(Sal)2 as nickel source and [Cr(en)3]Cl3.3H2O as chrome source. Effect of ball mill time, speed of ball mill, mass ratio of ball to powder and process control agent on morphology of as-prepared NiCr2O4 nanostructures was well studied. The morphology and microstructure of as-synthesized products were characterized by XRD, SEM, FTIR and EDX. Finally, the photocatalytic activity of nickel chromite nanostructures were studied by performing the photocatalytic degradation of an azo dye (Acid Red 88) at different irradiation time. The effect of irradiation time on the degradation of the azo dye was evaluated and the results showed that more than 99% of the dye was degraded in 150 min of irradiation. The pseudo-first-order kinetic models were used and the rate constants were evaluated with pseudo first order rate constants of 2.47×10-2 min-1. Also, the effect of particle size and morphology on the photocatalytic activity was evaluated.