Characterisation of Zinc Oxide and Cadmium Oxide Nanostructures Obtained from the Low Temperature Thermal Decomposition of Inorganic Precursors

Low temperature syntheses of zinc oxide and cadmium oxide nanoparticles are reported in this paper. The inorganic precursor complexes were prepared and characterised by hydrazine and metal analyses, infrared spectral analysis, and thermal analysis. Using appropriate annealing conditions, zinc oxide and cadmium oxide nanoparticles of average particle sizes around 13？nm and 30？nm were synthesised from the precursors by a simple thermal decomposition route. The synthesised nanoparticles were characterised for their size and structure using X-Ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and scanning electron microscopy (SEM) techniques. 1. Introduction This century has witnessed a tremendous escalation in the field of science and technology, for which the contribution of nanotechnology is much substantial. In the past decade, nanoscale research has opened revolutionary opportunities for a wide number of technological applications. Due to their special optical, magnetic, electrical, and catalytic properties and improved physical properties like mechanical hardness, thermal stability, or chemical passivity [1], metal oxide nanostructures are extensively used as paint pigments, cosmetics, pharmaceuticals, medical diagnostics, catalysts and supports, membranes and filters, batteries and fuel cells, electronics, magnetic and optical devices, flat panel displays, biomaterials, structured materials, and protective coatings [2]. Nanostructures based on zinc oxide and cadmium oxide are particularly interesting because of their n-type conductivity with a wide band gap (3.3？eV and 2.2？eV, resp.) which makes these materials more suitable for modern technologies. ZnO and CdO have promising applications in catalysts [3, 4], gas sensors [5, 6], solar cells [7, 8], paint pigments, and so on. There are several accepted techniques for the preparation of ZnO and CdO nanoparticles such as sol-gel method [9, 10], microemulsion method [11, 12], precipitation method, thermal decomposition [13], hydrothermal method [14, 15], chemical coprecipitation method [16], and thermal evaporation [17]. One of the simplest methods to obtain ZnO and CdO nanoparticles is the thermal decomposition of a suitable precursor. In this context, we have attempted to synthesise ZnO and CdO nanoparticles by the thermal decomposition route from the corresponding inorganic precursor M(cin)2·(N2H4)2 (M = Zn/Cd, cin = cinnamic acid) which involves low temperature, low cost, and low time consumption. 2. Experimental 2.1.