Preparation, Characterization and Functional Properties of Nickel Nanoparticles (NiNPs)

Abstract

In the present study, Nickel nanoparticles (NiNPs) were synthesized using Nickel (II)chloride hexahydrate (NiCl2•6H2O) as a precursor and hydrazine monohydrate (N2|H4•H2O) as a reducing agent with different molar ratios of 10 and 15 (〖 N〗_2 H_4/Ni^(2+)) in absolute ethanol at 60 °C. the yield was 90 % for both ratios. The as-obtained samples were characterized using (XRD), (TEM), (TGA-DSC) and (FTIR) spectroscopy. XRD studies confirmed that the synthesized nickel is highly crystalline with face centered cubic structure(fcc). TEM images revealed the formation of a nickel star-like shape when the molar ratio was 10 with an average size of 70-90 nm, and when the molar ratio was 15, a spherical particles shape with an average size of 50-80 nm. TGA-DSC revealed that nickel powders have an oxidization temperature of about 410 °C. FTIR showed absorption band at around 550-600 cm-1. Nickel nanoparticles (NiNPs) were used as catalyst to reduce heavy crude oil viscosity, results showed that 0.05 % NiNPs reduce heavy oil viscosity by ~ 51% evidenced by a slight change in density and API number of 1 % and 9.0% respectively. Results of Nickel nanoparticles (NiNPs) as an adsorbent in produced water treatment show that maximum removal of dissolved oil is 98 %. The adsorption data was inserted into Langmuir and Freundlich's isotherms to obtain adsorption parameters and adsorption capacity of NiNPs. Under Langmuir's isotherm, maximum monolayer adsorption capacity (qmax), KL, RL and R2 were 22,841 mg g-1, 0.001121 (L mg-1), 0.670 and 0.9775 respectively. in Freundlich’s isotherm model, the constants k, 1/n and R2 were 24.24, 1.005 and 0.9832 respectively.