The quest to synthesize nanomaterials with improved properties, but less undesirable effects on the environment necessitated this research. Zinc Oxide (ZnO) nanoparticles and zinc oxide-silver (ZnO-Ag), zinc oxide-copper (ZnO-Cu) nanocomposites were synthesized with pure eco-friendly dye extracted from Bridelia ferruginea, zinc acetate (Zn(CH 3 COO) 2 ) as host, copper acetate (Cu (CH 3 COO) 2 ), and silver nitrate (AgNO 3 ) as dopant precursors. Phytochemical screening of dyes showed high, presence of phenols and terpenoids. The nanomaterials were characterized by Fourier-transform infrared, X-ray diffraction, scanning electron microscopy with energy dispersive X-ray analysis, transmission electron microscopy and ultraviolet-visible spectroscopy. The results showed the capping agents in the dyes were responsible for reducing the bulk materials. The crystallinity of the nanomaterials were found to be 19.02, 18.98 and 18.90 nm for the ZnO, ZnO-Ag and ZnO-Cu nanoparticles respectively. The ZnO nanoparticles were flakelike in shape, whereas the Cu and Ag doped particles were spherical. An optical bandgap of 4.73 eV was recorded for the dye and 3.24 eV for the ZnO nanoparticles. This was narrowed to 3.18 and 3.13 eV by silver and copper dopant respectively. These results showed the nanoparticles as a potential agent for photovoltaics and other optical applications.

The inhibitory potentials of ethanolic extracts and four fractions of the stem bark of Ficus asperifoliaMiq. for the corrosion of mild steel were assessed using weight loss method, Fourier atomic absorption spectroscopy, scanning electron microscopy (SEM). The effects of varying immersion period, concentration of the inhibitors and temperatures for mild steel corrosion in 5 M HCl acid solution were carried out. A detailed kinetic reaction, thermodynamic (Ea, ∆H, ∆S) and adsorption isotherm studies were obtained. The crude extract of F. asperifolia (EFA) has the highest inhibition efficiency of 55%. The inhibitory efficiency of the four fractions of F. asperifolia (EFA) compared with the crude extract was in the order ethyl acetate > n-hexane > butanol > EFA > Aqueous. The inhibition efficiency was found to increase with increase in the extracts concentration but decreased with temperature. Corrosion rate increases with time but decreases with extracts concentration. The kinetic studies of the data followed a first order reaction. Thermodynamic studies revealed that corrosion inhibition may be due to spontaneous mixed adsorption of the plant constituents on the metal surface. Experimental data were fitted to Langmuir, Freundlich and Temkin adsorption isotherms. The plant investigated showed a good potential for green corrosion inhibitors. Investigation of phytochemical constituents showed that the extracts contain alkaloids, flavonoids, saponins, tannins anthraquinones and reducing sugars.

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Ethylene diaminetetraacetic acid (EDTA) functionalized graphene was synthesized from Nigerian coal using a chemical exfoliation method and the graphene was applied for the removal of Congo red dye from aqueous solutions.The synthesized coal graphene and the raw coal were characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) spectroscopy, Scanning electron microscopy and Energy (SEM)-Energy dispersive X-ray (EDX) spectroscopy. The SEM data revealed surface roughness which is enhanced in the prepared graphene while the EDX revealed an increase in carbon, the main constituent of graphene, from about 26% in the raw coal to about 80% in the prepared graphene. Various adsorption parameters, such as pH, contact time, concentration of Congo red and temperature, were varied for the removal of the dye using raw coal and the synthesized coal graphene. The Liu isotherm gave the best fit of the equilibrium data than the Langmuir, Freundlich and Dubinin-Radushkevich models. The maximum adsorption capacities of the raw coal and synthesized coal graphene at 25 °C are 109.1 mg/g and 129.0 mg/g, respectively. The Avrami fractional order kinetic model was the best model for description of the kinetic data. The model had the lowest values of standard deviation than the pseudo-first order and pseudo-second order models. The adsorption process of the two materials occurred via two stages as proved by intraparticle diffusion model. The adsorption process of the Congo red removal was spontaneous, feasible and endothermic. The study conclusively revealed the graphene nanomaterial to be a viable adsorbent for textile wastewater treatment.

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