Green synthesis and characterization of novel NiO/SiO2 nanocomposites from Citrus sinensis extract as an emulsion stabilizer for chemical enhanced oil recovery applications

Orange peels or Citrus sinensis peels are considered plant waste that can be discarded and become a nuisance to the environment. They can be used to create useful products that are economically advantageous. In this paper, Citrus sinensis peels extract was utilized to synthesize NiO/SiO 2 . The nanoparticles were characterised using various analytical methods including Scanning electron Microscopy (SEM), Electron Dispersed X-ray Fluorescence (EDXRF), Fourier Transform Infrared Spectroscopy (FTIR), Dynamic Light Scattering (DLS), and Thermogravimetric Analysis TGA. Based on the characterisation results, irregular NiO/SiO 2 nanocomposites with an average diameter of 16.6 nm were observed via the XRD analysis. The DLS gave a z-average hydrodynamic diameter of 41.5 nm. Approximately 87% of NiO and SiO 2 and 90% of Ni, Si, O in the synthesized nanocomposite were observed via EDXRF. The FTIR spectra confirms the presence of NiO and SiO 2 at wavelengths of 476 cm −1 and 1030 cm −1 . TGA analysis reveals a thermal stability of over 90% at a 300 °C. The analytical results confirm the successful synthesis of NiO/SiO 2 nanocomposite with a potential to be applied in various fields of science and engineering. The emulsion stability of crude oil emulsion using varying concentrations of NiO/SiO 2 was investigated by visual inspection and discovered to last for 15 days at a concentration of 1000 ppm in 3.5 wt% saline water suggesting its suitability for potential interfacial tension reduction and ultimately enhancing crude oil recovery.