Investigation on Structural Properties of Calcium Carbonate Synthesized by Precipitation, Gas Diffusion, and Thermal Chemical Vapour Deposition Method

This work entailed the structural properties of calcium carbonate synthesized by three different methods. The product was described and explained by elemental and size analysis. Three methods were compared and the products are described accordingly. Different methods used are precipitation method, gas diffusion method and thermal chemical vapour deposition (CVD) method. The chemical reactions involved, salt metathesis and carbonation reactions which were detailed and explained. The study found that among all the most viable method to produce the smallest, most uniform, well-distributed and most thermodynamically stable calcite is by thermal CVD method. This was done on FTO substrate at 400 Celsius for 60 minutes with 1.0 M calcium chloride as precursor with constant rate of 100 sccm Carbon Dioxide gas. This particular method produced rhombohedral calcite with crystallite size of 36nm and is suitable for further application of photo-catalytic and biosensor applications. Thermal CVD method also ensures minimal pre-cursors needed for production with high product yield. This study managed to detail additive-free method to synthesize thin film nanocrystalline calcite which is very rarely reported in the literature.