Research Articles (Chemistry)

Permanent URI for this collectionhttp://hdl.handle.net/2263/1724

This collection contains some of the full text peer-reviewed/ refereed articles published by researchers from the Department of Chemistry

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Now showing 1 - 20 of 698

Labdane diterpenoids from Leonotis ocymifolia with selective cytotoxic activity against HCC70 breast cancer cell line
Ncongwane, Jane Busisiwe; Tembu, Vuyelwa Jacqueline; Nkambule, Comfort Mduduzi; Kemboi, Douglas; Fouche, Gerda; Vukea, Nyeleti; De la Mare, Jo-Anne (MDPI, 2025-05-01)
Please read abstract in the article.
Sustainable Pb(II) remediation : efficacy and selectivity of Moringa Oleifera composite nanofibers
Ngulube, Ronald; Nombona, Nolwazi; Pillay, Letitia (Springer, 2025-10)
Please read abstract in the article.
Simultaneous photodegradation of acetaminophen and caffeine using a ZnO/CeO2/g-C3N4 nanocomposite
Chebwogen, Judith; Nyongesa, Francis W.; Mwabora, Julius M.; Ndungu, Patrick Gathura (Springer, 2025-10)
Please read abstract in the article.
Data from high temperature and high-pressure carbon dioxide sequestration experiments limited to 24 hours, performed on Platinum Group Metals mine tailings from the South African Bushveld Igneous Complex
Nkosi, Zakhele H.; Altermann, Wladyslaw; Doucet, Frédéric J.; Mohamed, Sameera; Phala, Karabo; Gauert, Christoph (Elsevier, 2025-12)
Please read abstract in the article.
Screening of metal additives in ABS polymer fuel for enhanced performance in hybrid rocket motors : a computational analysis using CEA
Ndlovu, Gail; Oboirien, Bilainu; Ndungu, Patrick Gathura (Elsevier, 2025-08)
This study investigates the potential of metal additives in acrylonitrile butadiene styrene (ABS) polymer fuel to enhance hybrid rocket motor (HRM) performance through computational analysis, Chemical Equilibrium with Applications (CEA), software. ABS was selected as the base fuel due to its thermoplastic nature, which allows for the creation of complex fuel geometries through 3D printing, offering significant flexibility in fuel design. Hybrid rockets, which combine a solid fuel with a liquid oxidiser, offer advantages in terms of operational simplicity and safety. However, conventional polymer fuels often exhibit low regression rates and suboptimal combustion efficiencies. In this research, we evaluated a range of metal additives—aluminium (Al), boron (B), nickel (Ni), copper (Cu), and iron (Fe)—at chamber pressures ranging from 1 to 30 bar and oxidiser-to-fuel (O/F) ratios between 1.1 and 12, resulting in 1800 unique test conditions. The main performance parameters used to assess each formulation were characteristic velocity (C∗) and adiabatic flame temperature. The results revealed that each test produced a different optimum O/F ratio, with most ratios falling between 4 and 6. The highest performance was achieved at a chamber pressure of 30 bar across all formulations. Among the additives, Al and B demonstrated significant potential for improved combustion performance with increasing metal loadings. In contrast, Fe, Cu, and Ni reached optimal performance at a minimum loading of 1%. Future work includes investigating B-Al metal composites as additives into the ABS base polymer fuel, and doing experimental validation tests where the metallised ABS polymer fuel is 3D printed.
Perspectives on aquatic emerging pollutant monitoring in sub-Saharan Africa with a focus on disinfection byproducts
Van der Merwe, Petra; Booysen, Amogelang; Forbes, Patricia B.C. (Oxford University Press, 2025)
The provision of clean water is of key importance in sub-Saharan Africa (SSA) where there is a rapid rate of urbanization. Aside from socio-economic factors, aspects such as a changing climate and polluted water sources create additional challenges towards achieving Sustainable Development Goal (SDG) 6: to "Ensure availability and sustainable management of water and sanitation for all". In order to allow for sustainable development and improved quality of life, water safety must be prioritized, which requires the effective monitoring of a range of potential water contaminants, including emerging chemical pollutants (ECPs), which pose risks to both human health and the environment. Here we provide perspectives on the current monitoring status of ECPs in the SSA region, with a focus on disinfection byproducts. Regulatory frameworks and reported monitoring practices are discussed in the context of suitability and accessibility for SSA. It was found that in recent years efforts to increase monitoring of ECPs has grown in some countries, although the majority of the countries in the region do not demonstrate these efforts.
Unseen threats in aquatic and terrestrial ecosystems : nanoparticle persistence, transport and toxicity in natural environments
Nthunya, Lebea N.; Mosai, Alseno Kagiso; Lopez-Maldonado, Eduardo Alberto; Bopape, Mokgadi; Dhibar, Subhendu; Nuapia, Yannick; Ajiboye, Timothy O.; Buledi, Jamil A.; Solangi, Amber R.; Sherazi, Syed Tufail H.; Ndungu, Patrick N.; Mahlangu, Oranso T.; Mamba, Bhekie Brilliance (Elsevier, 2025-08-15)
Although nanoparticles (NPs) are increasingly used in various industries, their uncontrolled environmental release presents a potential risk to water bodies, vegetation and human health. Although previous review studies evaluated the toxicity and bioaccumulation of NPs, their long-term ecological impacts and transport dynamics in aquatic and terrestrial systems remain unexplored. The current review examined the mechanistic bioaccumulation, transport and environmental persistence of NPs, highlighting the need for concurrent risk assessment, regulation and management strategies. The multifaceted nature of nanotechnology necessitates a balanced approach considering both the benefits of NPs and their potential environmental and health risks, requiring comprehensive risk assessment and management strategies. The complexities of NPs risk assessment, emphasizing the unique properties of NPs influencing their toxicity and environmental behavior are critically addressed. Strategies to mitigate NPs’ environmental impact include advanced monitoring techniques, regulatory frameworks tailored to NPs’ unique properties, promotion of green nanotechnology practices, and NP remediation technologies. Given the complexity and uncertainty surrounding NPs, integration of regulatory, technological, and research-based strategies is imperative. This involves detailed NPs characterization techniques providing basic data for environmental fate prediction models and understanding of biologically relevant risk assessment models to safeguard our environment and public health. In this study, the recent advances in NPs persistence, environmental transport modelling and toxicity mechanisms are uniquely integrated, providing a framework to ecological risk assessment and regulatory approaches.
Chalcogenide materials in water purification : advances in adsorptive and photocatalytic removal of organic pollutants
Akintayo, Damilola Caleb; Yusuf, Tunde Lewis; Mabuba, Nonhlangabezo (Wiley, 2025-07)
Chalcogenide-based materials, known for their unique physicochemical properties, emerge as promising solutions for the removal of hazardous organic pollutants, such as dyes, pharmaceuticals, pesticides, and herbicides, from water and wastewater. This review examines the latest developments in the synthesis, structural optimization, and application of chalcogenide materials for environmental remediation. The past decade has witnessed remarkable advances in controlling the composition and structure of chalcogenide materials at the atomic level. The development of precise synthetic methods enables the creation of complex hierarchical structures, heterojunctions, and hybrid materials, leading to significant improvements in photocatalytic efficiency, stability, and selectivity for various environmental applications. Key emphasis is placed on adsorption and photocatalysis as green technologies, offering efficient pathways for pollutant removal. Mechanistic insights into the interactions between chalcogenide materials and contaminants are explored, providing a comprehensive understanding of their performance. Furthermore, challenges such as toxicity, scalability, and operational stability are discussed alongside future prospects for integrating these materials into industrial-scale water treatment systems. This review aims to inspire continued innovation in sustainable water purification technologies using chalcogenides.
Enhancing hydrogen evolution in water splitting with pectin stabilized magnetite nanoparticles
Shibe, Nompumelelo N.; Mhlwatika, Zandile; Radhakrishnan, Shankara Gayathri; Nombona, Nolwazi (Wiley, 2025-10)
Please read abstract in the article.
Recent developments in organic radical inclusion in MOFs and radical MOFs
Ndamyabera, Christophe Adrien; Langmi, Henrietta Wakuna (Wiley, 2025-11)
Organic radicals are attractive materials due to their structures which contain unpaired electrons susceptible to charge transfer upon excitation. They possess potential properties such as optical properties, magnetism, and electrical conductivity. However, they are usually unstable impeding their further advancement and application. Organic radicals can serve as guest molecules in porous solids specifically metal–organic frameworks (MOFs) thereby gaining stability. MOFs are of interest due to their potential properties including large surface area and high adsorption capacity. Apart from their incorporation to form organic radical inclusion MOF hybrids, organic radicals can act as ligands in MOFs to yield radical MOFs. These hybrids and radical MOFs often exhibit enhanced properties such as improved catalytic, magnetic, optical, and sensing properties which make them promising for industrial applications. Herein, organic radical inclusion in MOFs and radical MOFs are reviewed. A brief background on organic radicals is presented. Different methods of integrating organic radicals (guests) in channels of MOFs (hosts) and the resulting changes in the physicochemical properties are documented. Furthermore, the use of organic radicals as ligands in the synthesis of radical MOFs is discussed as an alternative to organic radical–MOF inclusion compounds, and the ensuing physicochemical properties are highlighted.
Electrochemical reduction of CO2 in a zero-gap electrolyzer cell on a metal molecular electrocatalyst
Ndlangamandla, Simphiwe; Radhakrishnan, Shankara Gayathri (Wiley, 2025-08)
Please read abstract in the article.
Probing the inhibitory potential of halogenated symmetrical formamidine against MAO-A and MAO-B : structural elucidation, molecular dynamic simulation and DFT computational studies
Oladipo, Segun D.; Luckay, Robert C.; Olalekan, Samuel O.; Badeji, Abosede A.;; Yusuf, Tunde Lewis; Adeleke, Adesola A.; Matinise, Nonkosi (Wiley, 2025-10)
Please read abstract in the article.
Tuning optoelectronic properties of CsPbI2Br perovskite films via octadecyl ammonium iodide substitution
Thubane, Sandile Job; Nombona, Nolwazi; Diale, M. (Mmantsae Moche) (Springer, 2025-11)
Please read abstract in the article.
Value addition to African natural product-based drug discovery initiatives
Mayoka, Godfrey; Cheuka, Peter Mubanga; Moyo, Phanankosi; Dziwornu, Godwin Akpeko; Beukes, Denzil (American Chemical Society, 2025-08)
Natural products are vital to drug discovery, yet Africa’s vast biodiversity remains underutilized. This perspective examines barriers limiting Africa’s impact─such as weak infrastructure, limited translational capacity, and minimal integration of medicinal chemistry. We advocate for advancing beyond basic extraction to include systematic isolation, pharmacokinetics studies, and semisynthetic derivatization. Emphasis is placed on integrating AI, cheminformatics, and biotransformation, alongside embedding drug discovery training into academic curricula. Strengthening regional networks, fostering interdisciplinary collaborations, and securing Africa-sensitive funding are essential. Strategic implementation of these actions will enable Africa to harness its natural resources for global drug discovery and address local health challenges.
A qualitative study conceptualizing quality education in relation to sustainability : a focus on teacher education
Eloff, Irma; Dittrich, Ann-Kathrin; Mathabathe, Kgadi Clarrie; Grobler, Sunet; Modiba, Matabe Rosa; Agostini, Evi (Hapres, 2025-07)
BACKGROUND : Quality education in the context of sustainability is emphasized in the 2030 Agenda and articulated in Sustainable Development Goal 4 (SDG 4). This study aims to clarify how quality education is conceptualized in relation to sustainability within teacher education, which is essential for promoting sustainability in educational settings. METHODS : Using an interpretative qualitative approach, data was collected from 17 webinar focus groups over 16 months, involving 216 participants, including researchers, policymakers, teachers and students from various continents. Data was analyzed utilizing Kuckartz’s steps of categorization. RESULTS : Key themes include (1) the pivotal role of teachers and teacher educators in facilitating quality education, (2) social and educational justice in conceptions of quality education, (3) coherence in policy implementation gaps, and (4) contextual awareness in conceptions of quality education. CONCLUSIONS : The findings offer insight into how sustainability could be promoted by focusing on aspects such as the pivotal role of teachers, social and educational justice, coherence in policy implementation, and contextual awareness within educational settings.
Perspectives on the status and future of sustainable CO2 conversion processes and their implementation
Alli, Yakubu Adekunle; Ejeromedoghene, Onome; Dembaremba, Tendai O.; Adawi, Amer; Alimi, Oyekunle Azeez; Njei, Teckla; Bamisaye, Abayomi; Kofi, Alex; Anene, Uche Quincy; Adewale, Adekola Monsuru; Yaqub, Zainab Temitope; Oladele, Motunrayo Eniola; Jimoh, Lateefat; Oluwadadepo, Samuel; Ogunlaja, Adeniyi Sunday; Bin Xu, Ben (Elsevier, 2025-09)
The rapid rise in atmospheric carbon dioxide (CO₂) concentrations continues to threaten global climate stability, underscoring the urgent need for scalable, economically viable, and sustainable CO₂ mitigation strategies. Among emerging solutions, CO₂ conversion technologies offer a transformative pathway by enabling the utilization of CO₂ as a renewable carbon feedstock for the production of fuels, chemicals, and materials, thereby promoting a circular carbon economy. The review begins by exploring foundational CO₂ capture and pre-treatment methods, emphasizing advanced materials, as well as integration strategies that directly couple capture with conversion processes as a gateway to improved CO₂ conversion. Recent advancements in CO₂ conversion technologies, spanning thermochemical, electrochemical, photochemical, and biological domains are then covered. The integration of CO₂ conversion systems with renewable energy and industrial infrastructures is explored through case studies and commercialization efforts, highlighting opportunities for sector-wide decarbonization. Furthermore, the increasing role of artificial intelligence (AI) and machine learning (ML) in predictive modeling, catalyst design, and process optimization, as well as the techno-economic analyses that frame the practical deployment of these technologies is also presented. Persistent challenges including energy efficiency, long-term stability, product selectivity, and regulatory constraints are critically analyzed, and emerging solutions are proposed. The review concludes by outlining future research directions, including the development of next-generation technologies and strategies to promote interdisciplinary collaboration and public-private partnerships. By synthesizing cutting-edge advancements and identifying key barriers and opportunities, this work provides a roadmap for accelerating the global deployment of CO₂ conversion technologies toward a sustainable and decarbonized future.
Synthesis, structural characterization, biological and in silico evaluation of halogenated Schiff bases as potential multifunctional agents
Nthehang, Tsholofelo S.; Waziri, Ibrahim; Yusuf, Tunde Lewis; Oselusi, Samson Olaitan; Muller, Alfred J (Elsevier, 2026-02)
Please read abstract in the article. HIGHLIGHTS • Three new halogen substituted Schiff bases (SB1, SB2, and SB3) were synthesized. • Detailed spectroscopic and theoretical investigations were carried out. • All compounds were tested for cyto-toxicity, antioxidant, and antibacterial. • Biological study results revealed SB1 and SB3 as the most potent across all the assays, with SB1 been more superior.
Applications of graphitic carbonaceous materials in photosupercapacitors : recent breakthroughs and future perspectives
Mombeshora, Edwin Tonderai; Muchuweni, Edigar; Ndungu, Patrick Gathura (Elsevier, 2025-10)
Photosupercapacitors (PSCs) have recently attracted extensive research interest as one of the most promising energy storage devices owing to their self-charging attributes, small sizes, portability, lightweight, and ability to support emerging wearable electronics. With the recent emergence of high-specific energy density (Es) applications, including powering hybrid and electric vehicles, noteworthy research efforts are centred on increasing electrochemical performance, cost-effectiveness, and cycle lifespan of PSCs. This is being pursued by developing low-cost electrode materials with high reversible capacity and Es. One potential route to advancements in PSCs is turning to graphitic carbonaceous materials as promising electrode materials. Graphitic carbonaceous materials can be favourably derived from waste biomass, offer tailorable porosity and electro-active area, promote exciton dissociation during PSC charging by acting as electron transport layers, function dually as counter electrodes in solar cells and as electrodes in SCs, and are compatible with binder-free designs, among other merits. Therefore, this review focuses on the current understanding of the shortfalls and merits of using graphitic carbonaceous materials in PSCs. It also highlights the challenges and provides recommendations for improvement regarding PSC design, electrolyte selection, material compatibility, binder usage, fabrication processes, characterisation protocols, and components. Finally, the merits, demerits, and prospects of employing graphitic carbonaceous materials to advance PSC sustainability and performance are outlined.
Coordination complexes of N-((4-pyridyl)methyl)-1,8-naphthalimide and divalent metal halides : structures and solid-state fluorescence
Beebeejaun-Boodoo, B.M. Parveen; Rademeyer, Melanie (Taylor and Francis, 2025)
Please read abstract in the article.
Bioactive components in Vaccinium bracteatum Thunb. leaves : a seasonal transition study from spring to summer for health food development
Chen, Shuxin; Chai, Shuo; Cai, Jinhong; Zhu, Wei; Maharaj, Vinesh J.; Fu, Hongwei; Li, Shouxin (Springer, 2025-10)
The leaves of Vaccinium bracteatum Thunb. (VBTL) are an important natural treasure trove of raw materials to produce healthy foods, and the active compounds in VBTL play a key role. However, there has been a lack of systematic studies on the active compounds of VBTL throughout different periods. In this study, we investigated the changes in the active compounds of VBTL during three vital times: mid-spring in April, late spring in May, and early summer in June. We use proteomics and metabolomics to reveal the development of its nutritional and therapeutic aspects. The results showed that the abundance of proteins in the phenylpropanoid and flavonoid biosynthesis pathways was generally higher during the mid-spring stage. In contrast, flavonoids, which form the bitter and astringent flavor of tea, were lower, contributing to the production of VBTL-derived tea. The iridoid and iridoid glycosides associated with “wu-mi” staining were higher in late spring. VBTL were most resistant to oxidative stress in early summer. The abundance of proteins related to glutathione redox regulation and reactive oxygen species scavenging was higher at this stage. By studying the VBTL throughout three distinct periods, we can better understand the fluctuating properties of its active components. This study provides a solid foundation for determining the most advantageous moment for harvesting and maximizing its nutritional value.

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