Data for: Dominant role of trioctylphosphine on the particle size and various properties of CoO nanoparticles
2.1. Synthesis of CoO nanoparticles Cobalt acetate tetrahydrate (CAT), Co(CH3COO)2.4H2O (≥ 99 %) purchased from Sisco Research Laboratories Pvt. Ltd, OA (70%) and TOP (90%) from Sigma Aldrich were used as-received for preparation of CoO NPs. 2.1.1 First Method Typically, 2 g CAT, 8 ml OA and 2 ml TOP are mixed in three neck round-bottom flask and heated at the rate of 10 0C/min in nitrogen atmosphere. The pink-like crystals of CAT start to decompose turning solution colour to light blue around at 80 0C, to dark blue with increase in temper-ature and finally to dark brown at around 180 0C up to 200 0C at which 2 h is maintained; this indicates the formation of NPs. This solution is then cooled to 30oC, and centri-fuged by adding n-hexane to extract and wash the NPs. The washing is performed three times for remove the ac-cess OA and TOP, not bound on NPs surface. The particles dried at 60oC in vacuum drier are used for various charac-terizations. This sample was coded as CoO1. Another sam-ple prepared at 230 0C while other reaction conditions re-maining the same is coded as CoO2. 2.1.2 Second Method 0.25 ml of preheated TOP at 200oC is added in a solution of 2 g CAT and 8 ml OA, already degassed at 120-130oC for 30 min. The resulting solution is further heated to 230oC for 5.5 h under nitrogen atmosphere. The pink colour of CAT changes to blue and finally to a brownish colour due to the formation of CoO NPs. Cooling down to 30 oC, the reaction product is then washed and dried similarly as above; sample is denoted as CoO3. Other samples coded as CoO4, CoO5, CoO6, CoO7 and CoO8 for TOP concen-tration of 0.25 ml, 1 ml, 3 ml, 8 ml and 12 ml, respectively, with other conditions remaining the same are then prepared in 1.5 h. Additional samples coded as CoO9, CoO10 and CoO11 are then respectively prepared in 8 ml OA only, combination of 8 ml OA with 12 ml TOP, like CoO3, and 10 ml TOP only, at 260oC in 2 h in each with other condi-tions remaining the same to see the effect of surfactant/s and reaction temperate. To make NPs biocompatible, SiO2 was coated on the prepared powder of CoO8 using a standard method, described elsewhere23.