SYNTHESIS OF NICKEL COBALTITE SPINEL FROM COPRECIPITATED NICKEL-COBALT HYDROXIDE CARBONATE

A nickel-cobalt hydroxide carbonate precursor for the synthesis of nickel cobaltite was obtained by a coprecipitation technique. Thermal analysis and IR spectroscopy were used in the characterization of the basic carbonate and in the evaluation of some aspects of the spinel formation mechanism. The thermal decomposition of precursors with different Ni/Co ratio yields solid solutions NixCo3-xO4, 0 < x < 1 with a spinel structure and of high dispersity. The unit-cell parameter of NiCo2O4 synthesized at 570 K is 0.810 (6) nm. The specific surface area measured by the BET method is 90 m2/g, and the particle sizes range from 8.0 to 12.0 nm. A temperature-programmed reduction with hydrogen is also performed, and the resulting spectrum is interpreted.