Book of Abstracts

Development of CuO-Bi2S3 -Zeolite HY Composite Materials for Tetracycline Removal from Aqueous Solution: Adsorption Screening and Molecular Interaction Studies.

Osigbesan Aishat — Ahmadu Bello University, Zaria

Fasanya Opeoluwa O. — Baze University, Abuja

Oyegoke Toyese — Ahmadu Bello University, Zaria

Ajayi Olusegun A. — Ahmadu Bello University, Zaria

The presence of antibiotic residues such as tetracycline (TC) in water poses an increasing environmental concern due to their persistence and potential adverse effects on aquatic ecosystems and human health. This study focused on the design and development of CuO-Bi2S3-Zeolite HY composite materials for the removal of TC from aqueous solution. Seventeen (17) composites were formulated with different proportions of CuO, Bi2S3 and Zeolite HY using a simplex-lattice mixture-design approach. The composites were characterized by Fourier – Transform Infrared spectroscopy (FTIR) and their TC removal ability was evaluated through batch adsorption experiments. The FTIR results show the characteristic peaks of Cu-O stretching vibration at 500 – 600 cm-1, Bi-S vibrational mode at 430 – 470 cm-1 and the tetrahedral (T-O) asymmetric stretching of the Zeolite HY framework at 1000-1100 cm-1. Clear differences among the composites were observed, with TC removal ranging from 58.38 to 78.25 %. Composite PC2 exhibited the highest removal efficiency, while PC17 showed the lowest under the conditions investigated. To gain further insight into the interactions between TC and the semiconductor components of the composites (CuO and Bi2S3), semi-empirical PM3 calculations were carried out. The combination of experimental adsorption screening and molecular-level calculations provides useful information for understanding the behaviour of the composite materials. Overall, the findings indicate that combining CuO, Bi2S3 and Zeolite HY offers a promising and effective approach for developing multifunctional materials for the treatment of TC-contaminated water. This also contribute to the search for more sustainable approaches to managing pharmaceutical residues in the aquatic environment.

Keywords Tetracycline CuO - Bi2S3 - Zeolite HY composites adsorption molecular-level calculations water treatment.

Leveraging Locally Available Biomass for Sustainable Energy in Resource Limited Environments

Oluseyi Adewale Orelaja — Moshood Abiola Polytechnic,abeokuta Ogun State Nigeria

Raji, Taiwo Arimiyahu — Moshood Abiola Polytechnic, Abeokuta

Energy resilience in resource limited environments is a critical challenge for both civilian and defense applications. Biomass, as a locally abundant and renewable resource, offers a sustainable pathway to address these energy gaps. This paper explores the potential of leveraging locally available biomass—such as agricultural residues, forestry by products, and organic waste—to generate reliable energy in austere conditions. The study examines conversion technologies, operational benefits, and strategic implications for defense resilience. Results show biomass systems reduce emissions by over 80% compared to diesel generators, while offering cost effective and scalable solutions.

Keywords Biomass Defense Energy Gasification Anaerobic Digestion Pyrolysis Energy Security

Phytochemical Assessment of Sesanum indicum Leaf extract

Habib Sulaiman Adana — The Federal Polytechnic, Offa.

Mustapha Agbaa Abdulfatai — The Federal Polytechnic, Offa

Bilikis Kehinde Suberu. — The Federal Polytechnic, Offa

Olayinka Temitope Abiodun — The Federal Polytechnic,offa

Phytochemical assessment of Sesamum indicum Leaf Extract.

¹Adana, S.H., ²Abdulfatai, A.M., ³Suberu, K.B., ⁴Abiodun, T.O.
1,2,3,4 Department of Biochemical and Chemical Sciences, Federal Polytechnic Offa, P.M.B 420, Offa Kwara State.
*Corresponding Author email: habibadana@gmail.com
TELEPHONE: 08060614205

ABSTRACT
Sesamum indicum L. (sesame) leaves are traditionally consumed as food and applied topically to treat skin injuries and infections in various parts of Africa. Despite extensive research on sesame seeds and oil, the phytochemical profile of the leaves remains comparatively understudied.
This study aimed to qualitatively assess the phytochemical constituents of the ethanol extract of S. indicum leaves.
Fresh leaves were air-dried, powdered, and extracted by maceration in ethanol for 72 h. The concentrated extract was subjected to standard qualitative phytochemical tests for alkaloids, flavonoids, phenols and tannins, steroids and sterols, saponins, glycosides, and anthraquinones.
The ethanol leaf extract tested positive for alkaloids, phenols and tannins, steroids and sterols, saponins, glycosides, and anthraquinones. Flavonoids were not detected under the conditions employed.
The presence of these bioactive secondary metabolites provides a scientific basis for the traditional use of S. indicum leaves in the management of skin infections and injuries. The extract holds promise as a natural source of compounds for further development into topical skin-care formulations. Quantitative assays, antioxidant evaluation, and formulation studies are recommended.

Keywords Sesanum indicum phytochemical screening leaf extract ethanol alkaloids saponins tannins traditional medicine skin care Nigeria

Sustainable Biopesticides from Indigenous Azadirachta indica, Ocimum basilicum, and Zingiber officinale and its application on arthropods pest

Ishegbe Joyce Eko — Bingham University Karu Nigeria

Indiscriminate reliance on synthetic chemical pesticides presents acute ecological and health risks, driving urgent demand for bio-based botanical pest management strategies aligned with Sustainable Development Goals. In this study, essential oils and hydrosols were extracted via hydro-distillation from indigenous neem leaves (Azadirachta indica), sweet basil leaves (Ocimum basilicum), and ginger roots (Zingiber officinale). Oil yields were 7.2% (neem), 19.2% (basil), and 19.6% (ginger). Fourier-Transform Infrared (FTIR) spectroscopy identified principal bioactive functional groups: conjugated C=C stretching at 1640 cm⁻¹, carbonyl C=O stretching at 2117 cm⁻¹, and broad O-H/C-H stretching at 3265–3280 cm⁻¹, corresponding to key bioactive principles including azadirachtin, methyl cinnamate, and gingerol derivatives. Bioassays conducted on representative arthropod pests (Bephrateloides cubensis, fruit flies, Pharaoh ants, red spider mites, and mosquitoes) demonstrated rapid pest repulsion and mortality. Individual essential oils achieved pest mortality within 9 to 81 seconds, whereas a formulated 3-oil blend exerted potent synergy, achieving total mortality within 7 seconds (repulsion at 1 second). Hydrosols exhibited exceptional efficacy against mosquitoes (repulsion instantly to 2s, death in 3 to 7s) and arthropod pests (death in 12 to 30s). Comparisons with recent literature confirm that botanical essential oil blends and aqueous distillates offer viable, rapidly biodegradable, and non-toxic green biopesticides suitable for integrated pest management.

Keywords Biopesticides Hydrosols Azadirachta indica Ocimum basilicum Synergistic Pest Control.

The Effect of Sodium Sesquicarbonate (SSC) as a Softener on the Mechanical Properties of Manually-Extracted Sisal Fiber

Madiya Alka — University Of Abuja

Adiat Ibironke Arogundade — University Of Abuja

Dr Ishiaka Shaibu Arudi — University Of Abuja

This study investigates the spinnability and mechanical performance of sisal fibers subjected to chemical modification using sodium sesquicarbonate (Na₂CO₃·NaHCO₃·2H₂O), a mild alkaline agent, and sodium chloride (NaCl) as a softening additive. Sisal fibers, renowned for their tensile strength, durability, and cost-effectiveness, were manually extracted and treated under controlled conditions with varying concentrations of these agents. Standardized mechanical testing protocols were employed to evaluate tensile strength, elongation at break, and modulus of elasticity. The experimental findings reveal that sodium sesquicarbonate treatment significantly enhanced fiber elongation, with values ranging between 7–10%, thereby aligning sisal’s extensibility with that of cotton, a benchmark for wearable textiles. The optimal elongation was achieved at 9.84% under treatment conditions of 20% Trona at 125°C without NaCl addition, underscoring the critical role of alkaline modification in tailoring fiber ductility. Conversely, tensile strength exhibited a distinct dependency on NaCl concentration, increasing with higher salt content and reduced Trona levels. The maximum tensile strength recorded was 31.90 MPa at 125°C with 20% NaCl and no Trona, highlighting the synergistic influence of ionic interactions on fiber reinforcement.

Keywords sisal fibers sodium sesquicarbonate concentrations Mechanical properties

Assessment of sediment and water from Eleyele River in Oyo state for microplastics

Aborode Taofeek Oyeniyi — Federal Polytechnic Offa, Kwara State

Ayuba Waliyat Omobolanle — Federal Polytechnic Offa, Kwara State.

Oyinlola Khadijat Adekemi — Federal Polytechnic Offa, Kwara State.

Oyeniyi Khadijat Ayo — Federal Polytechnic Offa, Kwara State.

Assessment of sediment and water from Eleyele River in Oyo state for microplastics

1Aborode, T.O., 2Ayuba, W.O., 3Oyinlola, K.A., 4Oyeniyi, K.A

1,2,3,4 Department of Biochemical and Chemical Science
Federal Polytechnic Offa, P.M.B 420, Offa Kwara State.

*Corresponding Author email: aborodeoyeniyi@gmail.com

TELEPHONE: 08167237341

ABSTRACT

This study assessed the presence, concentration, and characteristics of microplastics (MPs) in water and sediment samples collected from the Eleyele River in Oyo State, Nigeria. The river is an important freshwater resource that supports domestic, agricultural and fishing activities for surrounding communities, yet it is increasingly exposed to plastic waste. Samples were taken from upstream, midstream and downstream locations and processed by density separation, visual identification under a stereomicroscope, and Fourier-Transform Infrared Spectroscopy (FTIR) for polymer characterisation.

Microplastics were confirmed in both matrices. Mean concentrations were 52.32 ± 22.8 particles L⁻¹ in surface water and 96.62 ± 45.3 particles kg⁻¹ in sediment. FTIR analysis identified polypropylene (PP) and polyethylene (PE) as the dominant polymers. Particles smaller than 1 mm accounted for the highest proportions (62 % in water; 65 % in sediment), indicating extensive fragmentation of larger plastic debris. Fibres were the most common shape (64 % in water; 67 % in sediment), pointing to domestic wastewater and urban activities as major sources.

The findings demonstrate significant microplastic contamination of the Eleyele River, with potential ecological risks to aquatic organisms and possible human-health implications for communities that rely on the river. Improved waste-management practices, public awareness and continuous monitoring are recommended to mitigate the threat of microplastic pollution in this and similar freshwater systems.

Keywords: Microplastics, Eleyele River, Freshwater pollution, Polypropylene, Polyethylene, Sediment, Water quality

Keywords Microplastics Eleyele River Freshwater pollution Polypropylene Polyethylene Sediment Water Quality

Biomaterials and Green Materials for Sustainable Industrial Development

Ilemona Isah — College Of Education

Elaochi Isaac — College Of Education

The increasing demand for industrial development and the growing environmental challenges associated with conventional materials have created a need for sustainable alternatives. Biomaterials and green materials provide promising solutions because they can be derived from renewable resources, reduce environmental pollution, and support efficient resource utilisation. This paper examines the potential of biomaterials and green materials in promoting sustainable industrial development, with emphasis on their applications in manufacturing, packaging, construction, agriculture, healthcare, energy, and environmental management. Materials derived from agricultural residues, plant fibres, starch, cellulose, chitosan, and other biological resources can transform waste into useful products while creating additional economic value. Green materials produced through environmentally responsible processes can also reduce the use of hazardous chemicals, excessive energy, and non-renewable resources. Particular attention is given to the availability of agricultural and biological resources in Nigeria and their potential for developing indigenous materials and industries. The paper discusses the benefits of adopting these materials, including waste reduction, employment creation, technological innovation, import substitution, and improved environmental sustainability. However, challenges such as inadequate infrastructure, limited technological capacity, high production costs, inconsistent raw-material quality, and weak links between research institutions and industries may hinder large-scale adoption. Strengthening research, innovation, supportive policies, investment, and industry–academia collaboration is therefore essential. The paper concludes that biomaterials and green materials can contribute significantly to resource efficiency, circular economy practices, environmental protection, and sustainable industrial development in Nigeria.

Keywords Keywords: Biomaterials green materials sustainable development waste valorisation green manufacturing.

EFFECT OF NAOH PRETREATMENT ON THE ELEMENTAL AND CRYSTALLOGRAPHIC STRUCTURE OF RICE HUSK ASH AND ON SELECTED RHEOLOGICAL PROPERTIES OF WATER-BASED DRILLING MUDS.

Toinpre Kuromioye Tekenah — Baze University, Abuja

Gbenga Godwin Oseke — Baze University, Abuja

Fasanya Opeoluwa O. — Baze University, Abuja

Rice husk ash is an abundant silica-rich residue in Nigeria and a potential local additive for water-based drilling mud. This study examined how sodium hydroxide (NaOH) pretreatment alters the elemental and crystallographic structure of rice husk ash, and how this affects mud rheology. Rice husk was calcined in two stages (700 °C for 2 h, then 900 °C for 2 h), either directly (RHA) or after treatment with 10%(w/w) NaOH and washing (BRH). The ashes were characterized by X-ray fluorescence (XRF) and X-ray diffraction (XRD). Each ash, and NaOH alone as a control, was added to a bentonite base mud at 6 g per 350 mL. Plastic viscosity (PV), gel strength and pH were measured following API RP 13B-1. NaOH pretreatment changed Si from 77.93 to 76.45 wt%, Na from below detection limit to 6.823 wt% and K from 4.823 to 7.43 wt%. XRD showed that NaOH pretreatment shifted the dominant reflection from 24.5° to 26.5° 2θ, indicating a change in crystalline phase composition. Base mud PV was 12.8cP. RHA raised PV to 15.7 cP at 6 g. BRH gave the largest increase, to 20.4 cP at 6 g, with a progressive rise in 10-min gel strength. NaOH alone gave only 9.0cP at 6 g, and mud pH differed little between BRH [9.91] and RHA [9.66]. The stronger BRH effect is therefore attributed to altered ash composition and silica structure, not free alkali. NaOH pretreatment offers a simple route to a more effective rice husk ash additive. Filtration control and thermal stability remain to be established.

Keywords rice husk ash alkali pretreatment silica crystallinity X-ray diffraction plastic viscosity gel strength water-based mud Rice husk ash Beneficiated rice husk

From Plastic Waste to Recoverable Energy: Polymer-Dependent Pyrolysis Performance and Fuel Characteristics

Izunna Francis Okaro — African University Of Science And Technology, Galadimawa, Abuja

Kamoru Adio Salam — University Of Abuja

Fadimatu Nyako Dabai — University Of Abuja

Plastic pyrolysis offers a means of recovering useful energy from plastic waste, but differences in polymer structure can influence energy recovery and product characteristics. This study compared the energy recovery behaviour of low-density polyethylene (LDPE), polypropylene (PP), and polystyrene (PS) during thermal pyrolysis in a semi-batch reactor. Total recoverable energy was determined from the energy contributions of the liquid and non-condensable gaseous products. PP recorded the highest total recoverable energy of 1.81 MJ, followed by LDPE at 1.68 MJ and PS at 1.59 MJ. Although PS produced a high liquid yield, it did not give the highest energy recovery, which shows that liquid yield alone may not adequately explain pyrolysis energy performance. The differences observed were linked to polymer molecular structure and the resulting degradation and product formation pathways. The recovered LDPE oil was further characterized using GC-MS and physicochemical tests. It contained mainly alkanes, alkenes and cyclic hydrocarbons within the diesel hydrocarbon range. The oil had a calorific value of 43.3 MJ/kg, flash point of 82.7 °C, pour point of − 23.3 °C, and cloud point of − 0.6 °C. However, its viscosity (18.0 mPa·s) and ash content (3.2%) indicate that further treatment would be required before direct use in diesel engines. The results show that polymer type influences product yield, total energy recovery and the practical fuel value of pyrolysis products.

Keywords Plastic pyrolysis Energy recovery Polymer structure Waste-to-energy Fuel properties

Production of Biodegradable Packaging Films from Moldy Caladium Tubers Reinforced with Banana Fibres

Chibuzor Blessing Anozie — Federal University Of Technology Owerri

The growing environmental burden of petroleum-derived plastic packaging has intensified the search for sustainable materials that are renewable, biodegradable, and economically accessible. Much of this research relies on edible starch sources, which places pressure on food security. This study addresses both concerns by converting two underutilized agricultural wastes—moldy caladium tubers and banana pseudostem fibres—into a functional biodegradable packaging film.
Starch extracted from moldy caladium tubers that would otherwise be discarded served as the film-forming matrix. Fibres obtained from banana pseudostems, a largely abandoned residue of banana cultivation, were chemically treated to remove non-cellulosic components and improve compatibility with the starch matrix. Chitosan was incorporated to strengthen the film structure and impart additional functional properties, while glycerol acted as a plasticizer to enhance flexibility. The films were produced by solution casting and dried under controlled conditions. Several formulations were prepared, each containing banana fibres subjected to different treatment conditions, allowing comparison of the effects of fibre modification on film performance.
The resulting films were evaluated for mechanical and physical properties, including tensile strength, water absorption, and permeability. These characteristics determine how effectively each film can contain, protect, and preserve packaged products under practical conditions.
The study demonstrates the potential of combining moldy caladium starch with banana pseudostem fibres to produce biodegradable packaging films. It offers a waste-to-value pathway that reduces agricultural waste, lowers dependence on edible starch sources, and supports the transition away from petroleum-based plastics. Findings on tensile behaviour, water absorption, and permeability provide useful insight into the structural and functional performance of the films and their suitability for sustainable packaging applications.

Keywords Keywords: biodegradable packaging caladium starch banana pseudostem fibre chitosan solution casting waste valorization

Proximate analysis on selected waste seeds and characterization of their seed oils

Akuetiemhe Aishat — Edo State University Iyamho

Muniratu Maliki — Edo State University Iyamho

Okodugha Deborah O — Edo State University Iyamho

Agricultural waste seeds represent an under explored resource. Furthermore, food shortage is on the increase due to factors such as rising climate changes, social and demographic pressure etc., amid rising demand. Repurposing agricultural waste to make high quality nutrients at low cost can be used to meet this urgent need. Thus, mango and Avocado seed were each collected from three (3) different locations in Etsako West, Edo State. Proximate properties of the seeds and characterization of their seed oils were evaluated. The percentage oil yield ranged from 7.42% (MFS II) – 8.77% (MFS III) for mango seeds (mean 8.08%) and 6.32% (AFS II) – 8.52% (AFS I) for avocado seeds. Moisture content ranged from 7.90% (APSII) – 9.62% (MSSI), while dry matter content varied between 90.38% (MSSI) - 92.20% (APSII). Ash content ranged from 2.36 % (MSSIII) –2.78% (MSSI) in mango seeds and 3.31% (APSII) – 3.95% (APSIII) in avocado seeds, indicating a higher mineral content in avocado seeds. Crude fat ranged from 6.03% (APSI) – 8.77% (MSSIII), crude fiber from 3.12% (MSSI) –7.35% (APSI) and crude protein from 0.086% (APSII) – 0.160% (MSSIII). Nitrogen-free extract (carbohydrate) constituted the major component of both seeds, ranging from 73.77% (APSII) –77.46% (MSSII), while the calculated calorific value ranged from approximately 289–306 kcal/100 g. The showed that the seeds are suitable sources of vegetable oils. However their high carbohydrate content indicates potential as alternative sources of carbohydrates in dietary foods and livestock feed formulations.

Keywords Agricultural waste management circular economy mango and avocado seed proximate analysis sustainable materials.

A Review on Synthesis Techniques and Structure–Sensing Relationships in ZnO/SnO2 Heterostructures for H2S Gas Detection

Stanley Chukwuebuka Ugochukwu — Federal University Of Technology Minna

Mohammed Isah Kimpa — Department Of Physics, School Of Physical Sciences, Federal University Of Technology, Minna, Nigeria

Abubakar Sadiq Yusuf — Department Of Physics, School Of Physical Sciences, Federal University Of Technology, Minna, Nigeria And School Of Engineering, Computer And Mathematical Sciences, Auckland University Of Technology, Po Box 92006, Auckland 1142, New Zealand

Uno Essang Uno — Department Of Physics, School Of Physical Sciences, Federal University Of Technology Minna

ZnO/SnO2 heterostructures have attracted significant interest in hydrogen sulphide (H2S) detection because the combination of the two oxides can produce interfacial effects that alter gas adsorption and charge transport. However, previous investigations have used varied preparation procedures and architectures, making a direct comparison of sensing data challenging. This review examines the link between synthesis approaches, structural characteristics, and H2S sensing behaviour in ZnO/SnO2 heterostructures. Electrospinning, ultrasonic spray pyrolysis, hydrothermal-assisted processing, and chemical vapour deposition are all studied and compared across the literature. The reviewed experiments demonstrate that the preparation procedure has a significant impact on the morphology and arrangement of the ZnO and SnO2 phases. Electrospun composite nanofibers, for example, have been reported to show high responses toward 50 ppm H2S at an optimal operating temperature of 250°C, while other studies highlight improved sensing from hierarchical and branch-stem heterostructures. These modifications are often linked to enhanced accessible surface area and effective heterojunction formation. Differences in gas concentration, operating temperature, and response definitions limit comparisons of reported sensor responses. The review thus focuses on identifying consistent structure-sensing links rather than ranking individual synthesis techniques. The identified trends provide a foundation for selecting and controlling synthesis conditions in future ZnO/SnO2-based H2S gas sensors.

Keywords Hydrogen sulphide (H2S) ZnO/SnO2 Heterostructures Gas sensor Synthesis methodologies

Box-Behnken Optimization of Ciprofloxacin Adsorption onto Phosphorus-Doped Chrysophyllum albidum Biochar-CuO Nanocomposite for Sustainable Wastewater Treatment

Ismaila Ayinde Oba — University Of Ilorin, Ilorin

Folahan Amoo Adekola — Department Of Industrial Chemistry, University Of Ilorin, Ilorin, Nigeria

Friday Onyekwere Nwosu — Department Of Industrial Chemistry, University Of Ilorin, Ilorin, Nigeria

Antibiotic residues in pharmaceutical effluents threaten water security and public health, demanding low-cost, sustainable remediation materials. A phosphorus-doped biochar-CuO nanocomposite (P-BC-CuO) was prepared from Chrysophyllum albidum seed biomass and applied to ciprofloxacin (CIP) removal from aqueous solution. The material was characterized by FTIR, SEM/EDX, TEM, XRD, XRF, TGA and BET analysis. Doping and CuO loading raised the BET surface area from 169.93 to 379.91 m²/g and pore volume from 0.16 to 0.35 cm³/g, with a 2.86 nm mean pore diameter indicating a mesoporous structure. The pHpzc was 6.6. A Box-Behnken design optimized initial CIP concentration, contact time, adsorbent dose and pH, yielding a highly significant quadratic model (p < 0.0001; adjusted R² = 0.9834; predicted R² = 0.9477) and a non-significant lack of fit (p = 0.5302); pH was the most influential factor. Optimum conditions (concentration 27.5 mg/L, dose 0.2 g, time 60 min, pH 8) gave an actual CIP removal of 94.8% against a predicted 95.1%. Equilibrium data fitted the Freundlich model best (R² = 0.9954), indicating heterogeneous multilayer adsorption, with a Langmuir capacity of 23.56 mg/g. Kinetics followed the pseudo-second-order model (R² = 0.9884), and a mean adsorption energy of 1.84 kJ/mol indicated physisorption. Thermodynamic analysis showed positive ΔH (16.76 kJ/mol) and ΔS (53.50 J/mol/K), indicating an endothermic process that became spontaneous (ΔG < 0) above about 313 K. These findings show that agro-waste-derived P-BC-CuO is a promising adsorbent for antibiotic-laden wastewater and supports circular-economy approaches to water treatment.

Keywords Ciprofloxacin Phosphorus-doped biochar CuO nanocomposite

Phytochemical Shielding in Chloride Media: Time-Resolved Mitigation of Mild Steel Degradation Using Aqueous Dioscorea Leaf Formulations

Blessing Jacinta Ifeanyichukwu — Sheda Science And Technology Complex, Abuja

Mercy Useh — Sheda Science And Technology Complex, Abuja

Chloride-induced corrosion poses persistent challenges for carbon steel infrastructure in marine and industrial settings, driving demand for sustainable mitigation strategies. This work investigates the protective capacity of aqueous Dioscorea spp. (yam) leaf extracts against mild steel degradation in 0.5 M and 1.0 M NaCl environments through systematic gravimetric monitoring. Specimens were exposed to saline media supplemented with 5 cm³, 10 cm³, and 15 cm³ of extract over 672 hours, with corrosion rates (CR, mm/yr) quantified at 168-hour intervals. Baseline measurements revealed inherently low corrosion activity in both NaCl concentrations (control CR: 7.0×10⁻⁵ to 1.0×10⁻⁵ mm/yr in 0.5 M; 1.1×10⁻⁴ to 2.0×10⁻⁵ mm/yr in 1.0 M), attributable to mild aggressiveness and possible surface passivation. Extract addition consistently suppressed corrosion kinetics, with the 15 cm³ dosage achieving terminal CR values of 3.0×10⁻⁶ mm/yr (0.5 M NaCl) and 1.0×10⁻⁵ mm/yr (1.0 M NaCl), representing up to 70% reduction relative to uninhibited controls at equivalent exposure times. A clear concentration-dependent trend emerged: higher extract volumes correlated with progressively lower corrosion rates across all timepoints. Furthermore, the monotonic decline in CR with prolonged immersion suggests time-dependent adsorption and formation of a cohesive phytochemical barrier on the metal surface. Comparative analysis indicates marginally enhanced inhibition efficiency in 0.5 M NaCl, implying that elevated chloride activity may partially compete with inhibitor adsorption. These findings establish Dioscorea leaf extract as a promising, biodegradable candidate for corrosion management in saline environments, while underscoring the value of agricultural biomass valorization in sustainable materials protection.

Keywords Chloride corrosion Dioscorea spp. Mild steel Saline media Phytochemical inhibition

Optimization of Lithium Recovery from Nigerian Spodumene Ore towards Sustainable Energy Applications

Aishat Yetunde Abdiulkareem — National Mathematical Centre/ University Of Ilorin

Ibrahim A. Suleiman — Federal Polythecnic Ayede

Olabode John Oluwasina — Federal Polytechnic Ayede, Ayede-oyo State

Nigeria possesses significant lithium-bearing pegmatite resources, yet their conversion into value-added lithium compounds remains relatively limited. This study investigated the optimization of lithium recovery from indigenous Nigerian spodumene ore towards sustainable energy applications using a pyro-hydrometallurgical process involving sodium carbonate–aluminium oxide roasting, aqueous leaching, carbonation, and crystallization. Response Surface Methodology (RSM) based on the Box–Behnken design was employed to optimize the effects of spodumene-to-flux ratio, roasting temperature, and roasting time on lithium extraction. The optimized condition, consisting of a 2:4 mass ratio of spodumene to combined sodium carbonate–aluminium oxide flux, roasting at 850 °C for 135 min, achieved 98.8% lithium extraction. X-ray diffraction analysis revealed substantial transformation of the original spodumene structure following roasting, with the formation of lithium- and sodium-bearing aluminosilicate phases, while subsequent leaching resulted in significant depletion of the major lithium-bearing phases. The optimized leach liquor was further processed through carbonation and crystallization to obtain a crystalline lithium carbonate product. FTIR analysis exhibited characteristic carbonate bands at 738.01, 857.28, 1088.38, and 1408.93 cm⁻¹, while the measured melting point of approximately 725 °C was consistent with reported lithium carbonate values. The findings demonstrate the technical feasibility of recovering lithium from Nigerian spodumene into a value-added compound with potential relevance as a precursor for lithium-based energy materials

Keywords Spodumene ore Roasting Extractions lithium Characterization

Sustainable Energy and Carbon Utilisation: Engineering Indium-Based Material for Electrochemical CO₂ Conversion to Liquid Fuels

Kayode Adesina Adegoke — 1 Department Of Chemistry, University Of Pretoria, Pretoria 0002, South Africa. | 2 Helmholtz-zentrum Berlin Für Materialien Und Energie Gmbh, Hahn-meitner Platz 1, Berlin 14109, Germany.

Sustainable pathways for converting carbon dioxide (CO2) into value-added fuels/chemicals are crucial for advancing secure and resource-efficient energy and industrial systems. Electrochemical CO₂ reduction (CO₂RR) represents a promising approach to sustainably integrate renewable electricity with carbon utilisation. However, its practical implementation is problematic due to sluggish reaction kinetics, mass transport limitations, competing reactions, and the necessity for catalysts that exhibit high activity, selectivity, and efficient charge transfer. This study investigates indium oxide (In₂O₃) as an effective electrocatalyst for the electrochemical reduction of CO₂ and formic acid (FA) into liquid fuels, emphasising the relationships among catalyst compositions, interfacial chemistry, and electrode architectures.
The potential-dependent behaviour of In2O3 in the presence of CO2 and FA was examined through cyclic voltammetry, linear sweep voltammetry, and infrared spectroelectrochemistry. Under cathodic conditions, the catalyst experiences a surface reconstruction that leads to the formation of In⁰-In₂O₃ interface. The presence of FA significantly modifies the electrochemical response, and spectroelectrochemical data indicates potential-dependent reactant consumption. The emergence of reduced intermediates offers mechanistic insight into the dynamic surface transformations occurring during the conversion process. The central materials engineering strategy involved incorporating a small quantity of polytetrafluoroethylene (PTFE) into In₂O₃ catalyst layer. This modification led to significant performance enhancements, achieving a 30-fold increase in current density and 15-fold reduction in ohmic resistance, which allows for electroreduction at lower potential. The In2O3/PTFE electrode generated methanol, ethanol, and isopropanol, achieving a combined Faradaic efficiency of 83% at a current density of 70 mA/cm2.
This study indicates that simultaneous enhancement of charge mobility, reaction mechanisms, and product specificity can be achieved through deliberate interface engineering, highlighting In2O3/PTFE as a potentially valuable platform for carbon utilisation. The findings hold significant relevance for incorporating the renewable energy, production of sustainable chemicals, and energy security, especially within developing industrial contexts in Nigeria and beyond.

Keywords Electroreduction Indium oxide current density carbon utilization spectroelectrochemistry

Leaching Agent Progress: From Strong Mineral Acids to Biodegradable Organic Chelators: A Review

Oluwakemi Christianah Adeyemi — Federal Polytechnic, Offa

Shittu Fatimah Bukola — Federal Polytechnic, Offa, Kwara State, Nigeria

Ayuba Waliyat Omobolanle — Federal Polytechnic Offa, Kwara State.

Idris Hafiz Yahaya — Federal Polytechnic, Offa

Sadisu Girigisu — The Federal Polytechnic Offa

The transition from conventional strong mineral acid leaching to environmentally benign biodegradable organic chelators represents a paradigm shift in hydrometallurgical processes. This review synthesizes recent advances (2020-2025) in sustainable leaching agent development, examining the progression from corrosive mineral acids (H₂SO₄, HNO₃, HCl) through organic acids (citric, oxalic, gluconic) to advanced systems including deep eutectic solvents (DES) and microbial-produced organic chelators. We document metal recovery efficiencies, mechanistic pathways, environmental impacts, and industrial scalability of these emerging technologies. A comparative analysis reveals that biodegradable chelators achieve recovery rates (85-100%) comparable to mineral acids while reducing toxicity, energy consumption, and waste generation. Applications span critical metals recovery from spent batteries, precious metal extraction from e-waste, rare earth element leaching, and base metal processing from primary and secondary sources. Challenges including solvent recyclability, viscosity limitations, and economic viability are identified, alongside strategic recommendations for technology advancement. This review provides evidence-based guidance for researchers transitioning to sustainable extraction paradigms aligned with circular economy principles.

Keywords Keywords: sustainable leaching biodegradable chelators organic acids deep eutectic solvents environmental impact metal recovery

New Advances in Processing Bismutite Ore Varieties as Raw Materials for Photocatalytic Applications: A Comprehensive Review

Ajibola Blessing Nihinlola — University Of Ilorin

Alafara Baba — University Of Ilorin, Ilorin, Nigeria

The development of various industries has given rise to a significant surge in environmental pollution in our environments. Thus, a need for the development of safe chemical processes for the degradation of the environmental pollution especially for water remediation processes become important. Bismuth, industrially obtained from a named Bismutite ore is a green and inexpensive metal that is relatively less toxic, and it has shown significant potential as a safer alternative for toxic elements including lead, cadmium, antimony and mercury. In addition, photocatalysis, an innovative oxidation process has been extensively used for water remediation processes due to its ease of operation and efficiency. In comparison to other conventional methods, photocatalysis is a promising technology for breaking down of toxic/organic pollutants in the environment by reducing/oxidizing toxins to H2O and CO2; and solar energy conversion. Therefore, this study gave a detailed review on some indigenous Bismutite Ores for its possible applications as photocatalytic materials in water remediation processes.

Keywords Bismuth Bismutite Ore Environmental Pollution Photocatalytic Applications