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N, N-dimethyl-N-(2-phenoxyethyl) dodecan-1-aminiumbromide has been evaluated as a corrosion inhibitor for mild steel in 1MHCl solution using potentiodynamic polarization, electrochemical impedance spectroscopy and atomic force microscope and Scanning electron microscope measurements. According to the experimental results, inhibition efficiency increased with increasing inhibitor concentration. Potentiodynamic measurements showed that the presence of inhibitor molecules decreases cathodic and anodic currents and shifts corrosion potential to a more positive potential region. Adsorption of the inhibitor molecules to the mild steel surface obeyed the Langmuir adsorption isotherm. Adsorption free energy was calculated from the adsorption isotherms as-31.33 to-39.0kJmol−1. The negative value of ΔG ads showed that the adsorption process is spontaneous for the studied conditions. In addition, measurements were carried out at different solution temperatures to determine temperature dependence of the adsorption process. At all studied temperatures, the inhibitor molecule protected mild steel with the same effect.

MgFe2O4 nanoferrites were synthesized by sol-gel and solution combustion synthesis (SCS) methods through green and chemical methods. Green and chemical methods for sol-gel were processed with use of lemon extract and citric acid, respectively. A green and chemical method for solution combustion synthesis was followed by using Phyllanthus acidus leaf extract and urea, respectively. The influence of synthesis approach on the behaviour of prepared nanoferrites were studied using powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and UV visible spectroscopy, vast variation in particle size, crystallinity, electrochemical and photocatalytic activity of the nanoferrites synthesized by various methods were witnessed. Powder X-ray diffraction (PXRD) result of prepared nanoferrites acquired by green and chemical approaches clarified phase structure as spinel and the crystalline size found to be around 11-24 nm. The spinel surface morphology was witnessed for the synthesized nanoferrites. The tetrahedral and octahedral sites of the prepared nanoferrites were confirmed by FTIR spectra. MgFe2O4 nanoferrites synthesized by green sol-gel approach exposed superior electrochemical activity by possessing very less charge transfer resistance. The results of EIS were correlated with the photocatalytic degradation of Rose Bengal dye. Photocatalytic property of the prepared nanoferrites was examined for photodegradation of Rose Bengal dye under UV-light.

MgFe2O4, ZnO and MgFe2O4-ZnO samples were successfully prepared through low temperature solution combustion route. The structural and morphological investigation were accomplished by PXRD, HRSEM, UV-visible and FTIR. The PXRD results point towards the reduced size of synthesized nanocomposites, which was further confirmed by HRSEM studies. Optical properties of the prepared samples were examined by UV-visible spectroscopy. The band gap seems to be widened for prepared nanocomposites compared to pure MgFe2O4. The photocatalytic degradation of methylene blue under sunlight was superior in contrast to pure MgFe2O4 and ZnO. MgFe2O4-ZnO (1:1) acts as the most effective photocatalyst activity compared to pure MgFe2O4 and ZnO. EIS data was proven to be an efficient tool for understanding the electronic properties for photocatalytic studies. The enhanced sunlight-driven photocatalytic activities of MgFe2O4-ZnO nanocomposite is supported by the factors such as quantization effect, band gap widening and efficient charge separation. MgFe2O4-ZnO showed excellent reusability with high photocatalytic efficiencies suggesting its suitability for solar photocatalytic applications. Additionally, scavenging test was conducted to know the role of all active species during photoelectrocatalysis. This work presents a facile and effective route for the construction of MgFe2O4-ZnO nanocomposites with intriguing structures and multiple functions.