Abstract:
This research examined the synthesis of nanomaterials from plants’ extracts for corrosion prevention and control. Plants extract from Chromolaena odorata (C. odorata), Jatropha curcas (J. curcas), Sida acuta (S. acuta) and Tridax procumbiens (T. procumbiens) were used for the synthesis of nanomaterials from silver nitrate solution. The leaves of the four selected plants were obtained, washed, dried and pulverized. The extract was obtained from the pulverized leaves using distilled water. The fixed ratio of plant extract and silver nitrate were mixed and kept in a microwave oven for reduction after which the synthesized nanoparticles were characterized by ultraviolet visible spectroscopy (UVS), X-ray diffractometry (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques. The width of the plane of the XRD pattern was determined using the multiple peaks and fit coupled with Gauss peak function of the Origin Software. Furthermore, the inhibitive property of both the synthesized nanomaterials and the bulk extract were evaluated on carbon steel by electrochemical and thermometric methods using a predetermined proportion of 7.5 and 10 ml.
The colour of the extracts changed from yellow to reddish brown indicating the formation of silver nanoparticles. An absorption peak around 200 nm to 430 nm observed in the UV-visible spectrum of the synthesized silver nanomaterials reveals the excitation and surface plasmon resonance of AgNPs. The particle size of the nanoparticles as calculated from the XRD pattern using Scherrer’s equation are 3.58 nm, 3.64 nm, 3.81 nm and 3.75 nm corresponding to C. odorata, J. curcas, S. acuta and T. procumbiens, respectively. From the result obtained from the electrochemical method, solution of the synthesized nanoparticles gave the optimum corrosion inhibition for J. curcas and T. procumbiens with the highest inhibition efficiency of 87.10 % and 97.10 % obtained at 10 ml. However, for S. acuta, the bulk extract gave the optimum inhibition efficiency of 96.15 % on the addition of 10 ml of the extract. The same trend was observed from the thermometric method. The SEM images of the coupon in the presence and absence of the extract revealed that the damages and roughness of the samples in the presence of the nanoparticles solution reduced considerably.
