Alaa Hani Alminshid

This work presents a cost-effective TiO₂ nanocomposite doped with Sn+2 (1.8wt%) and activated carbon (1 wt%) used as an active layer in hydrogen gas sensing applications. The prepared nanocomposite has a particle size of 46 ± 2 nm, roughness 4.31 nm, high surface area (202 ±11 m²/g), and a...

This study examined the effect of adding 50 parts per million [ppm] of either Co₃O₄ or Fe₃O₄ metal-oxide nanoparticles to biodiesel produced from used sunflower oil via transesterification on diesel-engine performance and exhaust pollution reduction. The two powders were first examined...

Currently, there is a lack of detailed knowledge about methane (CH₄) reactions on metal oxide surfaces. This reaction involves in different processes such as chemical looping combustion and catalytic carbon dioxide (CO₂) reforming of CH₄. In this study, in situ diffuse reflectance infrared Fourier transform spectroscopy was used to investigate CH₄ reaction on three transition metal oxides (CoO, CuO, and α-Fe₂O₃) which are commonly used in these processes at temperatures ranging from 100 °C to 700 °C. The results show that CH₄ is adsorbed on the metal oxide surfaces as methoxy and formate, and then the methoxy group reacts with the metal oxide lattice oxygen forming bicarbonate. Under the effect of the used reaction temperature, the bicarbonate decomposes to CO₂ and water vapor.

Lemon peel was examined in this work as innovative inexpensive biosorption material for cyanide (CN⁻) removal from aqueous solution. The influence of adsorbent amount, feed flow rate, CN⁻ concentration, and solution pH on the breakthrough and saturation points was determined. To determine the design parameters required to scale-up the system, this work explores six different kinetics models. The data showed that the breakthrough curve is highly dependent on the investigated parameters. The system showed perfect performance, achieving more than 99% removal of CN⁻ at the optimum conditions for the first 25 min. Furthermore, this work examined utilising the used adsorbent, saturated lemon peel with cyanide, as inexpensive rodent pesticide by tested on an outbred multi-purpose breed of albino rats and compare the results with the median lethal dose (LD₅₀) for those rats. The test results showed a foetal effect of the adsorption residue on the rats. This step will assure a safe method to dispose of the adsorption residue, as well as provide an inexpensive rodent pesticide, which increases the economic feasibility of this removal technique.

Given the importance of nanoparticle surface composition in nanotoxicology, analytical tools that can probe nanoparticle surfaces in aqueous media are crucial but remain limited. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy is a technique capable of in situ characterization of the liquid–solid interface to probe surface adsorption on nanoparticle surfaces in environmentally and biologically relevant media. Furthermore, given that the interfacial region in these media is dynamic, ATR-FTIR spectroscopy facilitates monitoring these dynamics by interrogating a layer of immobilized nanoparticles coated on the ATR element while changing the overlying aqueous phase. The molecular information acquired from this technique allows for the determination of the adsorption mode, including conformational and structural changes of the coordinating ligand, and can directly measure ligand displacement reactions. Furthermore, in some cases, ATR-FTIR spectroscopy can be used as a quantitative surface analytical tool. In this article, we briefly review the fundamentals of the technique and then provide several examples of using ATR-FTIR spectroscopy to probe nanoparticle surfaces in general with respect to: (i) the adsorption of different environmentally and biologically relevant coordinating ligands; (ii) competitive ligand adsorption and; (iii) the determination of kinetic and thermodynamic parameters. We have also investigated surface adsorption of TiO₂ nanoparticles in different biological media typically used for toxicity studies and show that the surface composition of TiO₂ nanoparticles depends to a large extent on the composition of the medium due to surface adsorption. This result has important implications for the interpretation of toxicity data as well as inter-comparisons between toxicity studies.