Rhoda Oyeladun Adegoke

Abstract: Soil, air, and water pollutions remain the major worldwide challenges for both human and eco-environment society. Decontamination of pollutants such as organic and inorganic compounds from an ecosystem remains a bottleneck over the years. Among several methods for removing pollutants, adsorption stands unique and usually simple and efficient. However, the versatility of the adsorption technique largely determines by the materials' sorption capacities which depend on the porous structures and surface property of the adsorbent. Metal-organic frameworks (MOFs) are a novel class of carbonaceous nanomaterials” having larger specific surface areas and their oxides have unique functional groups required for good adsorption processes. The applications of MOFs remain the focus of many kinds of researches in the last few years for effective removal of different contaminations from the soil, air, and water. This review presents some advancements in the usages of these novel MOFs for the adsorptive removal of different contaminants from the ecosystems. The study also highlighted some promising MOF adsorbents used for the effective removal of different pollutants including heavy metals, CO2, chlorinated volatile organic compounds (CVOCs), dyes, pesticides, food additives, veterinary, pharmaceutical and personal care products (PPCP), antibiotics, biological and chemical weapons, other industrial chemicals, etc. Still, the discovery of the actual feasibility and applicability of the MOFs usages as adsorbents on the commercial scales are highly needed. The reusability of these adsorbents is continuously desirable to reduce the cost and associated wastes produced from the pollutant removal processes. For more effective and practical applicability of MOFs, some frequent and unnoticed factors were also proposed as the challenges and prospects to foster the remarkable improvements in combating different pollutants. We further established that despite the existence of hitches and challenges associated with the use of MOFs, these materials are undeniably advantageous for decontaminating pollutants from wastewater, and upon sustaining efforts, their practical applications for water purification, separation, and other adsorption purposes will shortly be evident.

Abstract: Renewable energy has been a hot topic for sometimes due to its ability to minimize the global dependence on fossil fuels which is drastically declining, and more importantly the need to alleviate the emission of greenhouse gases. The uncontrollable releases of CO2 into the atmosphere as a result of excessive utilization of carbon-containing fossil fuel contributes significantly to the daily climate change and global warming. Numerous literature hasdemonstrated the uniqueness of Cu-based electrocatalysts to convert CO2 to useful fuels including alcohol, aldehydes and hydrocarbons. This review is an attempt to look into the expectation, realities of the mechanism on Cu electrodes and its prospect to convert CO2 to aldehydes, hydrocarbon and alcohol products by a way of utilizing CO2 for industrial feedstocks. In addition, we present some realized advancements on the pathways for CO2 reduction to C1–C3 products using Cu-based electrocatalytic materials and some expectations for the new mechanistic insights on the Cu electrodes for the electroreduction of CO2 to C3 and C4 products. The effective roles of electrocatalytic supports in achieving better activity and selectivity of the Cu-based electrocatalysts for the CO2RR to a practical significance were also suggested. To conclude this, several commonly overlooked factors were suggested as the challenges and prospects for fostering more improvements on the intrinsic electrocatalytic properties of the Cu-based materials.

Abstract: The investigation of the novel hybrid, 1, 2, 3-triazole moiety combined with pyrimidine derivatives against human esophageal carcinoma is an unexplored field of theoretical/computational chemistry. Also, the development of new drugs still remains a major challenge, cost-intensive and time-consuming, thus making the computational approach now a hot topic due to its ability to hasten up and aid the process of drug designs. Here, the use of the quantum chemical method via density functional theory (DFT) was employed in calculating molecular descriptors for developing the quantitative structure-activity relation (QSAR) model which predicts bioactivity of the selected 1, 2, 3-triazole-pyrimidine derivatives. Quantum chemical method implemented in Spartan 14, was used in calculating the molecular descriptors. The obtained results were imputed into Gretl and SPSS (software package for social sciences) to generate a novel QSAR model equation for human esophageal carcinoma (EC-109) through multiple linear regression. The relationship between the experimental and predicted inhibition efficiency (IC50) of 1,2,3-triazole-pyrimidine with EC-109 was calculated which gives good correlation results. QSAR was validated using CV.R2 and R a 2 . Fitting value (R2) of 0.999 with an adjusted fitting value ( R a 2 ) of 0.995 was obtained and the result of validating QSAR performance gave CV.R2 and R a 2 value that is greater than 0.6, signifying its appropriateness and dependability. Molecular docking through simulation using Discovery Studio 4.1, Autodock Tool 1.5.6 and AutodockVina 1.1.2 was also carried out to calculate the free energy of ligand-receptor interactions as well as ligand conformation in the receptor-binding site. The results obtained revealed the presence of hydrogen bond interaction of the ligands with the amino acids residue in the binding sites of the receptor. Conformation of the ligands was essential property for binding ligand with the receptor. Critical examination and the correlations between the IC50 and binding energy showed the activeness of ligand conformation in the gouge of the receptor with binding energy greater than the 5-fluorouracil (5- Fu) that was used as the standard compound.

Abstract: Electrochemical reduction of gaseous feeds such as CO2, CO, and N2 holds promise for sustainable energy and chemical production. Practical application of this technology is impeded by slow mass transport of the sparingly soluble gases to conventional planar electrodes. Gas diffusion electrodes (GDEs) maintain a high gas concentration in the vicinity of the catalyst and improve mass transport, thereby resulting in current densities higher by orders of magnitude. However, gaseous feeds cause changes to the GDE environment, and specific features are required to efficiently tune the product selectivity and improve reaction stability. Herein, with a comprehensive review of the challenges and advances in GDE development for various electrocatalytic reactions, we intend to complement the body of material-focused reviews. This review outlines GDE fundamentals and highlights key advantages of GDE over conventional electrodes. Through critical discussion about steps in GDE fabrication, and specific shortcomings and remedial strategies for various electrochemical applications, this review discusses connections, unique design criteria, and potential opportunities for gas-fed reactions and desired products. Finally, priorities for future studies are suggested, to support the advancement and scale-up of GDE-based electrochemical technologies.

Abstract: The scarcity and high cost of commercial noble metal-based materials necessitate the need for synthesizing alternative electrocatalysts for oxygen evolution reaction (OER). Many efforts put in place in addressing this problem have resulted in huge successes by employing different routes for synthesizing electrocatalysts, using different families of atoms and compounds. In this regard, this review describes the conceptual study of OER and an overview of electrocatalytic kinetics and theoretical modeling for oxygen evolution reaction. For in-depth understanding, a comprehensive and general overview of the recent developments in the OER electrocatalysts and efficient methods of testing the stabilities of catalysts to obtain reliable results are given. The study also includes some tutorial manuals for describing various parameters needed in electrochemical OER processes. We do hope they will be the useful guiding principles for the newcomers in this field. Interestingly, the emphasis is focused on describing different families of compounds used to synthesize high-performance OER electrocatalysts: which include transition metal compounds, polyoxometalates, carbon nanotubes, single atoms, layered double hydroxide, and non-metal compounds. Conclusively, important future perspectives to foster the advancement of this field are discussed.

Abstract: Abstract Oxide‐derived copper (OD‐Cu) electrodes exhibit unprecedented CO reduction performance towards liquid fuels, producing ethanol and acetate with >50 % Faradaic efficiency at −0.3 V (vs. RHE). By using static headspace‐gas chromatography for liquid phase analysis, we identify acetaldehyde as a minor product and key intermediate in the electroreduction of CO to ethanol on OD‐Cu electrodes. Acetaldehyde is produced with a Faradaic efficiency of ≈5 % at −0.33 V (vs. RHE). We show that acetaldehyde forms at low steady‐state concentrations, and that free acetaldehyde is difficult to detect in alkaline solutions using NMR spectroscopy, requiring alternative methods for detection and quantification. Our results represent an important step towards understanding the CO reduction mechanism on OD‐Cu electrodes.

Abstract: In this study, the samarium doped SbFeO3 nanoparticles/poly (ethylene oxide) was prepared via the hydrothermal and chemical technique. The prepared materials were characterized by X-ray diffraction, nitrogen adsorption/desorption isotherm, field-emission scanning electron microscopy, dynamic light scattering and UV–visible spectroscopy analysis. Photocatalysis degradation studies are conducted for methyl orange dye and benzene degradation by using the prepared materials in aqueous solution under sunlight irradiation. The degradation efficiency of methyl orange and benzene were 99.23%, and 93.87%, respectively. The solar degradation of the organic compounds indicated the substantial performance of Sm-SbFeO3/poly (ethylene oxide) photocatalyst rather than using the pure SFO nanoparticles. The performance of Sm-SbFeO3/poly (ethylene oxide) was examined for photocatalytic hydrogen evolution. The H2 production rate of were 76.74 µmol g−1 h−1.

Abstract: In this study an investigation of a model drug sorption onto cationic surfactant-modified natural zeolites as a drug formulation excipient was performed. Natural zeolite was modified with cetylpyridinium chloride in amounts equivalent to 100, 200 and 300% of its external cation-exchange capacity. The starting material and obtained organozeolites were characterized by Fourier transform infrared spectroscopy, zeta potential measurements and thermal analysis. In vitro sorption of diclofenac sodium as a model drug was studied for all surfactant/zeolite composites by means of sorption isotherm measurements in aqueous solutions (pH 7.4). The modified zeolites with three levels of surfactant coverage within the short activation time were prepared. Zeta potential measurements and thermal analysis showed that when the surfactant loading level was equal to external cation-exchange value, almost monolayer of organic phase were present at the zeolitic surface while higher amounts of surfactant produced less extended bilayers, ordered bilayers or admicelles at the zeolitic surface. Modified zeolites, obtained in this manner, were effective in diclofenac sodium sorption and the organic phase derived from adsorbed cetylpyridinium chloride was the primary sorption phase for the model drug. The Langmuir isotherm was found to describe the equilibrium sorption data well over the entire concentration range. The separate contributions of the adsorption and partition to the total sorption of DS were analyzed mathematically. Results revealed that that adsorption and partitioning of the model drug take place simultaneously.