Solution combustion synthesis of nickel sulfide composite powders

Nickel sulfide powders were synthesized through solution combustion method using a suitable combination of thiourea fuel as reducing/sulfidizing agent with glycine fuel as auxiliary reductant agent. Effects of fuel contents on the combustion behavior, phase evolution, microstructure and optical properties were investigated by infrared spectroscopy, thermal analysis, X-ray diffractometry, electron microscopy and diffuse reflectance spectrometry techniques. Single phase NiS2 powders were formed using thiourea fuel at higher content, while a mixture of nickel sulfide phases was appeared in the presence of glycine fuel. The amount of different sulfide phases was considerably dependent on the thiourea content. Particle size of the as-combusted powders increased with the increase of thiourea; while the existence of glycine fuel together with thiourea led to the bulky microstructure. Maximum photodegradation (similar to 56%) of methylene blue was achieved by as-combusted powders at a thiourea fuel to the oxidant molar ratio of 1, as a consequence of their high ability of light absorption.