The influence of surfactant type and calcination temperature on the formation of nickel oxide nanoparticles by chemical precipitation method

Abstract

In this study, the synthesis of NiO nanoparticles was carried out using a sequential precipitation and thermal degradation method. Nickel nitrate hexahydrate (Ni(NO3)26H2O) served as the precursor, while sodium hydroxide (NaOH) was used as the precipitating agent in a stoichiometric ratio. Various surfactants, including SDS, CTAB, Tween 80, PVP, NP-10 and PEG, were used as stabilizing agents. The obtained precipitates were calcined at different temperatures ranging from 300 to 600 degrees C. The effects of surfactant type and calcination temperature on the synthesized NiO morphology, particle size, and distribution were investigated. SEM, XRD, FT-IR, and BET analyses were used for product characterization. XRD analysis confirmed that the synthesized samples had a cubic (Fm-3 m) structure. The majority of the synthesized NiO particles have an average particle size of less than 60 nm, with nearly spherical shapes except for the CTAB-assisted sample, which also displayed rod-shaped structures. Besides, calcination temperature was found to play a critical role in tailoring particle size, surface area, and pore structure. As the calcination temperature increases, the average particle size and pore distribution increase, while the surface area decreases. The BET surface areas of NiO NPs range from 44 to 110 m2 g-1, with the highest value observed in the SDS-stabilized sample, which also has the smallest particle size. According to the BET analysis, the isotherms correspond to type IV(a) based on the hysteresis loop observed in the high relative pressure region (P/P-0) between 0.6 and 1.