Department of Chemistry

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A censorious appraisal of the oil well acidizing corrosion inhibitors
(Journal of Petroleum Science and Engineering 215, 2022) Solomon, Moses M.; Uzoma, Ifeanyi E.; Olugbuyiro, Joseph A.O.; Ademosun, Olabisi T.
Well acidizing is a common stimulation technique for maximizing the output of oil reservoirs. It helps to overcome the low permeability of wellbore by creating new flow channels or enlarging old ones. Corrosion challenge is encountered during the process since tubings are metallic. Corrosion inhibitors are the defence mechanism used in mitigating corrosion problem during acidizing. This review has identified and grouped acidizing corrosion inhibitors into organic-, and polymer-based. The performance of these inhibitors at temperatures of ≥60 ◦C and acid concentration of ≥15 wt% is considered. It is noted that greater percentage of studies revolve round the 60 ◦C. Above 100 ◦C, the number of scientific articles decreased considerably. Four classes of intensifiers for acidizing corrosion inhibitors have been identified: formic acid, potassium iodide, copper iodide, and antimony chloride. Their chemistries have been discussed. The research gaps identified include (i) scanty information on acidizing inhibitors at temperatures ≥150 ◦C, (ii) limited information on natural polymers and plant biomaterials as acidizing inhibitors, (iii) scanty information on the mechanism of inhibition at temperatures ≥150 ◦C, and (v) limited information on the composition of corrosion products under acidizing conditions. Thus, recommendations for future researches have been given.
Advances in nanoparticles as drug delivery systems: A review
(Scientific African, 2025) Akomolafe, Oluwatobi Abayomi; Akinsiku, Anuoluwa Abimbola
The use of nanoparticles in the pharmaceutical sector as drug carriers is rapidly growing, with many benefits over conventional drug delivery procedures. These nanoscale carriers are composed of biodegradable biocompatible materials, delivering therapeutic agents to the target with precise control and mitigating unwanted side effects. Despite numerous reports, many research gaps remain; thus, opportunities to improve the specificity and effectiveness of nanoparticle-based drug delivery for various illnesses, such as cancer, cardiovascular disease, infectious diseases, and central nervous system (CNS) disorders, are identified. The advances in nanoparticle-based drug delivery and their tremendous potential for revolutionising how drugs are delivered to treat disease are discussed. This review provides an overview of the various types of nanoparticles, including lipid-based, polymeric, natural polymers, and inorganic nanoparticles, which are being developed with their unique physical and chemical characteristics. It also reveals the strategies employed to enhance the targeting efficacy and stability of these nanoscale carriers in nanomedicine. The advantages, mechanisms, future direction, and drawbacks of each nanoparticle-based drug delivery system in target therapy and personalised medicine are well reviewed. Thus, addressing the identified gaps will be crucial for the clinical translation of nanoparticle-based therapeutics.
Amino-functionalised mesoporous silica nanoparticles for the delivery of isoniazid and its metal complexes
(Materials Chemistry and Physics Volume 326, 2024) Tella, Josephine Oluwagbemisola; Adekoya, Joseph Adeyemi; Ajanaku, Kolawole Oluseyi; Banerjee, Rajkumar; Patra, Chitta Ranjan; Pavuluri, Srinivasu; Sreedhar, Bojja
The effective delivery of poor water-soluble anti-tubercular drugs such as isoniazid to their target sites is a major factor that has made it difficult for tuberculosis to be eradicated. Isoniazid derivatives and nano-particulate drug delivery systems are explored as one way to address this limitation. This study investigated the use of amino functionalised mesoporous silica nanoparticles (MCM-41) as nano-carriers for the delivery of isoniazid-based metal complexes, Cu–INH and Fe–INH. The Sol-gel method was used to synthesise the nano-carriers, which produced a series of well-ordered nano-carriers. Their physicochemical properties were modified through surface functionalisation with amino groups via post-grafting synthesis. The isoniazid based metal complexes were incorporated into the nano-carriers using rotary evaporation. The nano-carriers were characterised using X-ray diffraction (XRD), Zeta potential, Fourier Transmission Infra-red (FT-IR), Brunaeur Emmett Teller (BET), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Thermogravimetric analysis (TGA). These characterisation techniques confirmed the successful surface functionalisation of the nano-carriers with amino groups and their encapsulation with INH, Cu–INH and Fe–INH. The amino-functionalised nano-carriers were observed to have the highest drug loading capacities and entrapment efficiencies within the range of 7.85%–19.31 % and 39.26%–96.53 %, respectively. The release rates of INH, Cu–INH, and Fe–INH from the nano-carriers were also studied in Phosphate Buffer Solution (PBS) with pH of 7.4 and 5.4 using ultraviolet–visible spectroscopy. The cumulative release rates of INH, Cu–INH, and Fe–INH from their nano-carriers depended on their release media's textural properties and environmental conditions. Amino functionalised nano-carriers had high release rates, with A-MCM 41+Cu–INH having the highest of 37.09 % in PBS at 5.4 after 24 h. The cumulative data obtained was fitted into Zero order, First order, Hixson Crowell, Higuchi, Korsmeyer Peppas and Weibull models. The Hixson Crowell, Korsmeyer-Peppas, and Weibull models fitted well with correlation coefficients (R2) of 0.9813, 0.9769 and 0.9802, respectively, for MCM-41+INH in PBS of pH 5.4.
Antimicrobial and cytotoxicity evaluation of Annona muricata-based silver-cobalt nanoparticles on WEHI 164 cell line
(Results in Chemistry, 2025) Akinsiku, Anuoluwa Abimbola; Odaudu, Ruth Opiotu; Ejilude, Oluwaseun
The harsh chemicals in conventionally fabricated metal nanoparticles have limited their applications for biomedical purposes. As part of green and sustainable chemistry in this study, an aqueous extract of indigenous Annona muricata was a reductant in preparing silver‑cobalt nanoparticles (Ag Co NPs) for therapeutic appli cation. The reaction progress and rate of formation of nanoparticles were monitored with a UV–visible spec trophotometer. The functional groups, structural morphology, and elemental composition of the Ag Co NPs were confirmed using FTIR, SEM, TEM, and EDX techniques, respectively. This study evaluated the cytotoxicity potential of 21.38± 8.0 nm Ag–– Co NPs on the WEHI 164 cell line for the first time, using an MTT assay and the antimicrobial potential of Ag Co NPs against six microorganisms. The characteristic wavelength of absorption was observed between 400 and 450 nm. The antimicrobial test showed evident growth inhibition by Ag Co NPs on P. aeruginosa, Candida albicans and Aspergillus niger. The in vitro cytotoxicity evaluation on the WEHI 164 cell line indicated that the Ag–– Co NPs were cytotoxic at an IC 50 dosage of 84 concentration-dependent. Hence, the Annona muricata synthesised Ag μ g/mL, and the cytotoxic potential was Co NPs are potential pharmaceutical drug candidates.
Biosynthesis, characterization, and antimicrobial study of zinc oxide nanoparticles using Adonida merrilli leaf extract
(International Conference on Science, Engineering and Business for Driving Sustainable Development Goals, 2024) Owoeye, Taiwo Felicia; Bamisaye, Abayomi; Adekoya, Joseph Adeyemi; Afolalu, Sunday A.; Monye, Stella Isioma; Ojo, Augustine Oluwatyin
The utilization of plant-mediated methods to synthesize metal oxide nanoparticles (NPs) is becoming increasingly popular due to its simplicity, low cost, and environmental friendliness. Adonida merrilli leaf extracts in aqueous form were used for the production of nanoparticles of zinc oxide (ZnO). scanning electron microscope with energy dispersive X-ray (SEM-EDX), Fourier transform infrared spectrometer (FTIR), X-ray diffractometry (XRD), and UV-Vis spectrophotometer were accustomed to analyze the ZnO nanoparticles. The antibacterial effects of the ZnO NPs was examined on pathogens such Salmonella, Candida, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa.XRD indicate spherical crystalline nanoparticles with an average particle size of 73.82 nm. Zinc oxide nanoparticle absorption wavenumber at 715 cm-1 was seen in the FTIR, and EDX chemical mapping confirms the elemental composition of zinc and oxygen. For Candida, Salmonella, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus measured Zones of Inhibition (ZI) values are 30.00, 36.00, 32.00, 40.00, and 36.00 mm, and the measured Minimum Inhibitory Concentration (MIC) values are 7.81, 1.95, 7.81, 1.95, and 3.90 mg/mL, respectively. The results of this investigation, as shown by the MIC and ZI values, point to the possible use of Adonida merrilli extract in the synthesis of highly crystalline Zinc oxide nanoparticles (ZnONPs) as an alternative medication.
Complexes of SCN and dithiol ligands for solvothermal green synthesis of high indexed binary PbS and SnS semiconductor nanoparticles
(Journal of the Indian Chemical Society Volume 102, Issue 6,, 2025-06) Adekoya, Joseph Adeyemi; Oyeku, Pelumi Olusola; Edidiong, Sunday Sam; Adeniyi, Adeleke Ayoola; Almalki, Abdulraheem S. A; Mersal, Gaber A.M.; Ibrahim, Mohamed M.; Revaprasadu, Neerish
COVID lockdowns significantly affect statewide atmospheric fine aerosols in India after excluding long-term pollution patterns and time-lag effect
(Atmospheric Environment Volume 343, 2025-02-15) Etchie, Tunde O.; Etchie, Ayotunde T.; Pinker, Rachel T.; Kumar, Prashant; Swaminathan, Nedunchezhian
Atmospheric fine particulate matter (PM2.5 , near-surface concentrations when size is ≤ 2.5 μm) affects global climate and human health. India alone accounts for a quarter of the global PM2.5-related health burden. Studies in India, mostly in urban areas, have reported significant declines in PM2.5 concentrations because of COVID-19 lockdown. These studies did not consider the long-term PM2.5 patterns and time-lag effect (inter yearly variations in PM2.5 concentrations carried forward from one period to another due to interannual shifts in meteorological conditions). Since the studies focused primarily on urban areas, not covering rural/remote areas where pollution may rise during lockdown, it is still unclear what impact lockdown had on statewide pollution levels in (AODf India. Here, we examine whether significant changes in fine-mode aerosol optical depth : columnar PM2.5 ) occurred statewide across India because of lockdown after excluding the confounding variables. We found a substantial decrease in AODf in a few (28%) states/territories. The declines were significant (ANCOVA; α = 0.05) in some Northeastern states/territories: Sikkim (29%), Arunachal Pradesh (24%), Nagaland (5%), Mizoram (4%) and Uttarakhand (3%). However, in most states/territories, AODf increased significantly because of lockdown. The lockdown-associated hardship caused more people to rely on polluting cooking fuels, thereby increasing residential emissions, particularly in rural areas. At city-level, we found significant reductions in near-surface PM2.5 concentrations due to lockdown. These declines were comparable or greater than previously reported. Also, there were significant reductions in AODf (PM2.5 concentrations) at state (city) levels resulting from previous environmental intervention measures. If not accounted, previous environmental intervention measures can significantly bias lockdown effect estimates in India.
Determination Of Nutritional Potential Of Cymbopogon Citratus (D.C.) Staph By Atomic Absorption Spectroscopy And Its Health Benefits
(International Journal of Innovative Research and Advanced Studies (IJIRAS) Volume 5 Issue 3,, 2018) Umoh, Emmanuel Michael; Sam, Edidiong Sunday; Udoh, I. I.
Lemon grass (Cymbopogon citratus) was processed for analyses. They were sorted and chopped into bits. They were sundried for 12hrs, oven dried for 24hrs at 60oC and pulverized. Digestion was carried out according to AOAC 2000 and analysed for P, Mg, K, Na, Se, B, Co, Fe, Zn, Mn, Cu and Ca contents using Unicam 939/959 Atomic Absorption Spectrophotometer. Out of these twelve “botanical based minerals”, the most abundant was potassium followed by magnesium, phosphorus and calcium the least being boron. Most nutritional problems in Nigeria experienced by the vulnerable groups - the children and the elderly are due to mineral deficiencies in unwholesome or processed foods. Minerals usually obtained from synthetic mineral supplements are inadequate for the rural population due to high cost of procurement and at times adulteration. Most of them are toxic to susceptible individuals. Lemon grass is very effective in „Ajurvedic‟ medicine because of the “botanical based minerals” and bioactive compounds therefore taken in adequate quantities will help in the improvement of general health.
Environmental Radioactivity Monitoring and Radiological Impact Assessment of Agbara Industrial Area, Ogun State, Nigeria
(Polytechnica, 2024) Usikalu, Mojisola Rachael; Orosun, Muyiwa Michael; Akinwumi, Akinpelu; Babarimisa, Idowu Olaegbe; Arijaje, Theophilus Emuobor; Mohammed, Adamu Usman
Abstract This study assessed the naturally occurring radioactivity of 40K, 238U, and 232Th, which pose a significant threat to human health, particularly when their concentrations exceed the threshold. Background radiation levels were measured at two specific locations, Access Bank and Market areas, across a total of forty (40) sample points. The measurements were taken using a calibrated RS125 Gamma Spectrometer (a portable NaI [Tl] detector) designed in Canada, in conjunction with a global positioning system (GPS) to accurately record the research coordinates within the Agbara industrial area, Ogun State, Nigeria. The mean activity concentrations of the primordial radionuclides were 177.87 Bqkg-1, 20.01 Bqkg 1, and 52.90 Bqkg-1 for 40K, 238U, and 232Th, respectively. More so, the in-situ measured dose rate (DR) ranges between 12.18 nGyh-1 (Access Bank area) and 97.95 nGyh-1 (Market area), with an average value of 47.22 nGyh-1. The average measured and estimated absorbed dose rates were within the safe limit of 57 nGyh-1 provided by UNSCEAR. However, the measured dose rates exceeded the recommended limit in ten locations, while measured activity for thorium exceeded the world average value for over half of the study locations. Although all estimated radiological parameters were within recommended threshold values, suggesting the low risk of exposure to higher levels of ionising radiation in most locations in the Agbara industrial area, there is a potential cancer risk for individuals who have resided in the area for 70 years or more due to long-term exposure to ionising radiation.
Exploring layered lithium-rich spinel composite cathodes for lithium-ion battery obtained by the solution combustion-mechanochemical synthesis
(Journal of Alloys and Compounds Volume 1038, 2025-08-20) Ehi-Eromosele, Cyril O.; Ajayi, Samuel O.; Shaaban, Ibrahim A.; Assiri, Mohammed A.; Hessien, Mahmoud M.; Abiaziem, Chioma V.; Sunday, Sam E.; Mathe, Mkhulu K.
In this study, layered lithium-rich oxides (LLO) cathode materials were modified with different amounts of the spinel phase to form integrated layered-layered-spinel (LLS) hetero-composites [0.5Li2 MnO3 ꞏ (0.5 − x)LiNi0.5 Mn0.3 Co0.2 O2 ꞏ xLiMn1.5 Ni0.5 O4 (0.05 ≤ x ≤ 0.25)] using a facile solution combustion mechanochemical synthesis method for the first time. The XRD results indicate that all the LLS materials have distinct layered and spinel phases with R3m, C2/m and Fd3m space groups. Notably, the initial coulombic efficiency of the LLS materials increased with increase in the spinel content but showed a reduction both in their charge and discharge capacities. The LLS doped with 5 % spinel content (651LLS), exhibited the best electrochemical performance compared to the ones doped with 15 % spinel content, gave the smallest particle size and the largest unit cell volume. Consequently, the 651LLS cell delivered the highest initial discharge capacity of 279.58 mAh g⁻¹ and a capacity retention of 84.71 % after 50 cycles at a current density of 10 mA g⁻¹ within a voltage window of 2.0 – 4.8 V. Additionally, the 651LLS cell demonstrated superior rate capability with the average capacities 275, 225, 200, 155, and 90 mAh g⁻¹ at 10, 20, 50, 100, and 200 mA g−1. This enhanced performance is attributed to the optimised spinel amount and the smaller particle size which facilitated faster Li-ion transport during cycling. Also, the optimal electrochemical behaviour of the 651LLS cathode is linked to its optimum spinel content (∼5 %) which contributed to its improved structural stability. The results show that the amount of spinel in these LLS materials must be carefully tuned in relation to the operating cycling parameters to produce optimum electrochemical performance.
High-voltage LiNi0.5Mn1.5O4 cathodes for Li-ion batteries obtained by sol–gel combustion method: effects of fuel-type and silver doping
(Sustainable Energy & Fuels, 2025-09-28) Ehi-Eromosele, Cyril O.; Ajayi, Samuel O.; Ikebudu, Jude N.; Abiaziem, Chioma V.; Mathe, Mkhulu K.
High-voltage LiNi0.5 Mn1.5 O4 (LNMO) cathode materials are highly desirable for the fabrication of next-generation lithium-ion batteries (LIBs). In this study, citric acid, glycine, and sucrose fuels were used to optimize the structural and electrochemical properties of LNMO materials obtained by sol–gel combustion synthesis (SCS). The experimental results showed that the type of fuel used in the SCS process influenced the enthalpy of combustion, crystallite size, morphology, cationic disorder and electrochemical properties of the LNMO materials. XRD results indicated that all the LNMO materials have a phase-pure spinel structure with the Fd3m space group. The glycine fuel composition produced LNMO material (LNMO-G) with the least crystallite size, less cationic disorder and the highest crystallinity compared with those having the citric acid fuel (LNMO-C) and sucrose fuel (LNMO-S) compositions. As a result, the LNMO-G cell delivered the highest first discharge capacity of 115.83 mA h g−1 and retained 80.06% of its initial capacity after 200 cycles at a current density of 1C. Moreover, the LNMO-G cell had the best rate capability compared with the LNMO-C and LNMO-S cells, with a discharge capacity of 60 mA h g−1 at a rate of 2C between 3.50 and 5.30 V. Furthermore, Ag doping (LNMAO) improved the rate capability and Li-ion kinetics of the LNMO-G cathode material. The LNMAO cathode achieved a reversible discharge capacity of 100 mA h g−1 at a rate of 2C between 3.50 and 5.30 V. These findings show that LNMO cathode materials can be optimized for ultra-high-voltage (>5.0 V) performance in LIBs for advanced applications.
Improving cycling performance and high rate capability of LiNi0.5 Mn0.3 Co0.2 O2 cathode materials by sol-gel combustion synthesis
(Journal of Physics and Chemistry of Solids, Volume 196, 2025-01) Ehi-Eromosele, Cyril O.; Liu, Xinying; Mathe, Mkhulu K.
The layered LiNi0.5 Mn0.2 Co0.2 O2 (NMC532) material displays capacity loss and poor rate performance even though it is a widely used cathode in commercial Li-ion batteries (LIBs). In this work, the structural and electrochemical performance of the NMC532 cathode were optimized using the fuel-to-oxidizer ratio assisted sol-gel combustion synthesis (SCS). It was shown that the fuel-to-oxidizer ratio markedly influenced the exothermicity of the combustion reaction which affected the crystal structure, morphology, and electrochemical performance of the final NCM532 materials. The fuel lean (FL) composition produced NMC532 cathode materials with the biggest crystallite and particle sizes, less cation mixing degree and better layered structure compared with the fuel stoichiometric (FS) and fuel rich (FR) compositions. The FL cell presented an initial discharge capacity of 180 mAh g−1 and the highest capacity retention of 92.2 % when it was cycled at 0.1 C between 2.5 and 4.4 V. Also, the FL cell displayed exceptional rate capability with the average capacities reaching 180, 178, 175, and 173 mAh/g at current densities of 1 C, 3 C, 5 C, and 10 C, respectively between 3.0 and 4.6 V. The EIS tests and dQ/dV plots showed that the FL cell both had the least impedance and polarization. The superior electrochemical performance of the FL material was ascribed to its optimized structural properties. Furthermore, the electrochemical results also show the influence of voltage window and current density on the performance of the NMC532 cathode materials.
Interaction of black carbon surface mass with meteorological variables and spatial pattern across the 36 states of tropical Nigeria
(Remote Sensing Applications: Society and Environment Volume 35, 2024-08) Etchie, Ayotunde Titilayo
Black carbon (BC) has been linked to cardio-pulmonary diseases and lung cancer. It is also the second largest contributor to climate change, after carbon dioxide (CO2 ), Effective mitigation of BC is of much benefits, but it requires detailed knowledge of its spatial distribution, as well as the influence of local meteorology on the spread of the pollutant. Many countries in sub-Sahara Africa including Nigeria, lack data on BC level. There is also limited information on meteorological impact on BC spatial distribution. This study therefore assessed the spatial and temporal distribution of BC across the 36 states of Nigeria and the influence of meteorology on the pollutant spread. Data on BC surface mass (BCMASS) and seven meteorological variables (air temperature, relative humidity, rainfall, wind speed, planetary boundary layer height (PBLH), atmospheric pressure and wind direction) were obtained from Modern Era Retrospective analysis for Research (MERRA-2). Spatial distribution of BCSMASS across 36 states of Nigeria, and interaction with meteorology was studied using correlation analyses, Bayesian ridge regression with marginal maximum likelihood estimation, and a Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. There was significant (p < 0.05) variation in BCSMASS across the states. The meteorological variables, except wind direction, significantly influenced BCSMASS and they accounted for 63% of the variation. Five-day backward trajectory modelled for each month of the year revealed that northern Nigeria is majorly under the influence of the dry and dusty tropical continental wind, and this could partially account for the lower BCSMASS concentration in the region, compared to southern Nigeria. Based on population-weighted exposure, states in southern Nigeria, especially the south-eastern part, should be prioritized in planning mitigation, for effective climate action.
Natural and anthropogenic biomarkers in recent dated sediment cores from Refome Lake, SE Nigeria: environmental implications
(Environ Earth Sci, 2016) Oyo-Ita, Orok Esu; Oyo-Ita, Inyang Okon; Sam, Edidiong Sunday; Ikip, Ekpo Offem; Ugim, Ugim Samuel
Natural and anthropogenic biomarkers characteristics of two recent sediment cores collected toward the shoreline and center of Refome Lake (RS and RC; 30 cm long), southeastern Nigeria, were investigated in order to reconstruct past environmental conditions and asses humans-induced changes on the local ecosystem over the last century. Results from sediment bulk properties such as total organic carbon (TOC; 0.12–0.54%; mean— 0.26 ± 0.9%), total nitrogen (TN; 0.01–0.05%; mean— 0.03 ± 0.7%) and total inorganic carbon (TIC; 0.03–0.37%; mean—0.14 ± 1.0%) contents as well as TOC/TN (5–25; mean—11.55 ± 1.4) suggested slightly higher contribution from allochthonous over autochthonous organic matter (OM), lowered by low primary production and the characteristic Niger Delta sheltered basin morphology predominated by sandy lithology. Evaluation of molecular proxies such as carbon preference index (CPI(C24–C35); 1.23–1.74: mean—1.58 ± 0.4), carbon maxima (Cmax—17, 19, 26, 27, 29), long-chain/short-chain hydrocarbons (LHC/SH-C; 0.77–2.25, mean—1.52 ± 0.3) and Paq, (0.21–0.61, mean–0.45 ± 0.3) as well as C29/C27 (0.89–2.67; mean—1.53 ± 0.2) indicated an admixture slightly predominated by microbial OM (algae/bacteria) in the most recent top layer (RC1, 0–5 cm) of RC core and slightly more enhanced terrestrially derived OM in the middle layer (RS4, 15–20 cm) of RS core. The later sediment layer deposited at ca. 1947–1964 coincided with the period of greater wash-in of land-derived OM (associated with tree logging/forest clearing for foot path extension and farmland preparation authorized by the European settlers) occasioned by intense rainfall. The occurrence of gammacerane and 18a-oleanane in low levels in the lower and upper layers revealed trace contamination by petroleum hydrocarbons imported into the Nigerian economy prior to independence in 1960 and utilization of Niger Delta oil after 1960 following departure of the colonial masters (the British), respectively.
Nutritional Indices, Phytochemistry, and the In Vitro Antioxidant Activity of Carrot Fortified Tomato Concentrate
(Wiley Journal of Food Quality, 2024) Ademosun, Olabisi Theresa; Adebayo, Abiodun Humphrey; Ajanaku, Kolawole Oluseyi
Researchers are constantly looking at the development of functional foods from local materials that o.er both nutritional and therapeutic potentials. e study investigated the proximate composition, antioxidant capacity, and phytochemical pro0le of di.erent compositions of formulations produced from tomato and carrot. e plant materials were sourced locally, dried to a uniform weight, and milled using a mechanical blender. Nutritional indices, viz., proximate analysis, were analyzed using a standard protocol. e phytocompounds present in the formulations and their in vitro antioxidant activities were analyzed using spectrophotometric methods. e results for proximate composition showed low moisture content in formulations (0.44 ± 0.015–0.54 ± 0.021%). e protein content of the formulations (16.51 ± 0.217–17.94 ± 0.134%) was signi0cantly higher than that of carrot alone (8.41 ± 0.154%). Similarly, the crude fat was elevated in the formulations (0.31 ± 0.008–1.63 ± 0.017%) compared to tomato alone (0.10 ± 0.399). However, these values were lower than the values obtained for carrot alone (8.72 ± 0.009%). e energy value for the formulations ranged from 87.01 to 93.30 kcal, which was low compared to carrot alone (136.89 kcal). Phytochemical screening showed the presence of terpenoids, cardiac glycosides, saponins, phenols,
Photocatalytic Activity of Green Mixed Matrix Membranes for Degradation of Anionic Dye
(Green Chemistry for Sustainable Water Purification, 2022-12-27) Oladipo, Gabriel Opeoluwa; Alayande, Samson Oluwagbemiga; Ogunyinka, Opeyemi O; Akinsiku, Anuoluwa Abimbola; Akinsipo-Oyelaja, Oyesolape Basirat; Ofudje, Edwin Andrew; Bolarinwa, Hakeem S.; Akinlabi, Akinola Kehinde; Msagati, Titus. A.M.
Anionic dye is a notable constituent of textile effluent, which renders water unsafe for human and animal use. A notable approach to mitigating effluent is the use of membranes. In this study, a mixed matrix technique was adopted for the preparation of composite membranes. The composite membranes consist of crumb rubber filled with nanoparticles, respectively. The membranes were characterized by Fourier transform spectroscopy, scanning electron microscopy coupled with energy dispersive x-ray, thermogravimetric analyser, and drop shape analyzer. The photocatalytic activities of the mixed matrix membranes were investigated with anionic dye in the UV/visible region. Photocatalytic activity of composite membranes showed high degradation with an apparent rate constant. This study presents a rubber-based membrane for wastewater treatment.
Recent developments strategies in high entropy modified lithium-rich layered oxides cathode for lithium-ion batteries
(Inorganic Chemistry Communications, 2025-02) Ajayi, Samuel O.; Dolla, Tarekegn H.; Bello, Ismaila T; Liu, Xinying; Makgwane, Peter R.; Mathe, Mkhulu K.; Ehi-Eromosele, Cyril O.
Lithium-rich layered oxides (LRLOs) are of intense interest and are regarded as one of the best cathodes for next-generation Lithium-Ion batteries (LIBs). LRLOs are favored due to the low cost of production, high energy densities, voltage, and specific capacity. LRLOs suffer from irreversible capacity loss, poor rate capability, voltage, and capacity fade, which in turn limit their full practical applications and commercialization. Therefore, strategies such as surface coating, surface treatment, composition optimization, and elemental doping have been explored to enhance the structural and electrochemical performance of LRLO. Nevertheless, high entropy (multiple elements) doping has proven to be a very effective strategy due to its simplicity and expansion of LRLO lattice interplanar spacing without damaging their original structure. It is worth noting that there has been little research work on high entropy strategies for modifying LRLO cathode. Thus, the aim of this review is current update on high entropy strategies for modifying LRLO cathode materials.
Recent developments strategies in high entropy modified lithium-rich layered oxides cathode for lithium-ion batteries
(ECS Meeting Abstracts, Volume MA2025-01,, 2025) Ajayi, Samuel O.; Ehi-Eromosele, Cyril; Liu, Xinying; Mathe, Mahlanyane Kenneth
LiNi0.5Mn0.2Co0.2O2 (NMC532) is a widely used cathode material in commercial lithium-ion batteries; however, it suffers from capacity degradation and poor rate performance. In this study, sol-gel combustion synthesis (SCS) with a controlled fuel-to-oxidizer ratio (fuel stoichiometric (FS) and fuel-rich (FR) compositions, the fuel-lean (FL)) respectively, was employed to improve the structural and electrochemical performance of the NMC532 cathode. The fuel-to-oxidizer ratio was found to significantly impact the exothermicity of the combustion reaction, which subsequently influenced the morphology, crystal structure, and electrochemical performance of the synthesized NMC532 material. The FL composition produced a well-defined layered structure, the largest crystallite size, and the lowest degree of cation mixing compared to the FS and FR compositions. The FL cell exhibited an initial discharge capacity of 180 mAh/g and the highest capacity retention of 92.2% when cycled at 0.1 C within a voltage range of 2.5–4.4 V. Additionally, it demonstrated superior rate capability, delivering capacities of 180, 178, 175, and 173 mAh/g at current densities of 1 C, 3 C, 5 C, and 10 C, respectively, within a voltage range of 3.0–4.6 V. The electrochemical impedance spectroscopy (EIS) measurements confirmed that the FL cell had the lowest polarization and impedance. The superior electrochemical performance of the FL cathode was ascribed to its improved structural properties.
Source Characterization and Historical Trend of Sedimentary PAHs from Refome Lake, South–South Nigeria
(Aquat Geochem, 2017) Oyo-Ita, Inyang O.; Oyo-Ita, Orok E.; Ikip, Ekpo O.; Sam, Edidiong S.; Ugim, Ugim S.
Polycyclic aromatic hydrocarbons (PAHs) released from diverse sources passing through water column carry information into the sediment where they can be used to assess the environmental status of an ecosystem over specified geologic time frame. The vertical distributions of PAHs in two recent sediment cores (RS and RC, 30 cm long) from Refome Lake, South–South Nigeria,were investigated using gas chromatography–mass spectrometry in order to evaluate their sources and historical trends of deposition over the last ca. century. The total PAHs (TPAHs—sum of parent and retene) concentrations ranged from 66.99 ng/g dry weight (dw) at the middle layer ofRCcore (RC3 10–15 cm) to 182.24 ng/gdwat the near-bottomlayer of RS core (RS5 20–25 cm) with amean of 102.21 ± 24.32 ng/g. The elevated TPAH level at the near-bottom layer of the RS core, corresponding to geologic time-frame ca. 1930–1947, coincided with the period of inhabitation of the European settlers along the lake’s catchments when utilization of coal and/or coal products for domestic/recreational activity was at its peak. A decline in TPAH levels up-cores thereafter reflected the periods of gradual evacuation of inhabitants of the lake area hinterland following the departure of theWhite after the Nigerian independence in 1960. Evaluation of PAH category according to ring size coupled with data from specific molecular ratios revealed inputs dominated by wood/coal combustion with a moderate contribution from petrochemical/liquid fossil fuel exhaust emissions and a minor diagenetic sources. Principal component analysis result not only distinctively separated RS fromRCcore samples but also revealed that the RS samples weremore impacted by wood/coal combustion emissions than the RC, while liquid fossil fuel exhaust emission dominated the RC over the RS samples. Although short-range eolian transport did play a role in the delivery of PAHs to the lake, localization of source contamination was more important.
Stable carbon isotope and n‑alkane distributions in sediment cores from saline and freshwater Gabu lakes, southeast Nigeria: environmental implications
(Environmental Earth Sciences, 2023) Oyo‑Ita, Inyang O.; Sam, Edidiong S.; Oyo‑Ita, Orok E.; Arnold, Elliott T.; Inyang, David O.; Werne, Josef P.
Studies on the utilization of molecular and isotopic proxies for the characterization of organic matter (OM) sources and environmental conditions in lakes have been well-documented globally. Nevertheless, inland lacustrine salt basins remain less well-studied, particularly in tropical sub-Saharan Africa. In this study, we quantified OM sources and evaluated the effects of salt deposit and barite mining on the distribution of n -alkanes in saline and freshwater Gabu lakes sediment cores, southeast Nigeria using elemental, bulk carbon isotope ratios and biomarker distributions. Our results indicate a system inundated with comparable proportions of vascular plant leaf waxes (mean = 56.6%) and submerged/floating macrophytes (mean = 41.1%) with minor contribution from algae/photosynthetic bacteria (mean = 2.3%). The scenario indicates a shallow water system that predominantly preserved long chain n-alkanes derived from vascular plant leaf waxes and macrophytes. The capacity of macrophyte to biosynthesize long chain n-alkanes most likely reflects adaptation of these organisms to partial exposure to the atmosphere. The occurrence in moderate abundance of C17 and C19 n-alkanes and the near absence of other low molecular weight (LMW) n-alkanes in the saline lake was linked to the effect of salt stress. The absence of LMW n-alkanes in freshwater lake may be associated with slow barite hydrolysis likely to cause acidification. Our results have demonstrated that long chain n -alkanes of terrestrial and submerged/floating macrophyte origins are better preserved under conditions of low salinity and acidification in inland shallow lakes than those derived from algae/bacteria