Introduction:
Metal oxide Nanoparticles have certain industrial and technological properties that include optical, magnetic, electrical, catalytic, mechanical strength, thermal stability and chemical properties. The production of metal oxide nanoparticles is carried out using a number of chemical methods, which include sol-gel, reduction-oxidation, hydrothermal hydroxide oxidation, and metal salts decomposition methods. Time efficiency, production cost, ability to operate continuously, and production rate are the parameters that have been considered in order to choose the best synthesis method for a specific application. Solution combustion synthesis (SCS) or sol-gel auto-combustion method appears to be a promising method due to low production cost, because it requires low-cost precursor materials and equipment. It’s feasible to fabricate a wide range of nanoparticles and metal oxides, and more efficiently compared to some other methods [1]–[5].
The perovskite oxides are mixed metal oxides with the general formula of ABO3, where A is larger cation usually an alkaline-earth or rare-earth metal cation and B is the smaller cation, usually, a transition-metal cation (e.g., Mn, Co, Fe, Ni,) surrounded by six oxygen atoms in an octahedral coordination [6]. However, perovskite oxides, LaMO3, in which M is a transition-metal containing Co, Fe, Ni, have been used in a variety of applications, including gas sensors (CO, propane and ethanol sensing) as nanostructures’ film, hollow spheres and mesoporous nanowires, nanoparticles, porous and fibrous structures [7]–[11], photocatalytic reduction of CO2 with visible light, electronic devices, electrochemical systems, solid oxide fuel cell, solar cells, and catalysts [11]–[17]. Different methods have been uses to synthesize and develop perovskite phase of LaCoO3 as nanoparticles and nanowires, over the years; these include thermal decomposition, hydrothermal, microwave-assisted coprecipitation, co-precipitation, sol-gel, and combustion methods [10], [17]–[22].
The purpose of this research is to synthesize nanoparticles of LaCoO3 perovskite in a single step by combining the sol-gel and auto-combustion steps. Investigation of the influence of fuel ratio and different fuel on nanoparticle characteristics has been done. These particles can be used as a catalyst in the decomposition of nitrogen oxide gases (NOx).