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The Africa Capacity-Building Initiative is a Royal Society programme funded by the former UK Department for International Development to develop collaborative research between scientists in sub-Saharan Africa and the UK. Initially, four institutions were involved in the Chem4Energy consortium: Cardiff University in the UK and three African partners, the Kwame Nkrumah University of Science and Technology, Ghana, the University of Namibia and the University of Botswana, soon also including the Botswana International University of Science and Technology. The Chem4Energy research programme focused on 'New materials for a sustainable energy future: linking computation with experiment', aiming to deploy the synergy between state-of-the-art computational and experimental techniques to design and optimize new catalysts and semiconductor materials for renewable energy applications, based on materials that are abundant and readily available in African countries. The Chem4Energy consortium has achieved ambitious research goals, graduated seven PhD students and delivered a high-quality cross-disciplinary training programme in materials science and simulation techniques relevant to renewable energy applications. Since 2021, the extended consortium, including North-West University and the Centre for High-Performance Computing in South Africa, has remained active through an annual Chem4Energy conference series, with the sixth meeting taking place in Namibia in April 2025., Competing Interests: We declare we have no competing interests., (© 2024 The Author(s).)

Two azo dyes, ( E )-3-(benzo[ d ]thiazol-2-yldiazenyl)-4-hydroxy-2 H -chromen-2-one (3CBD) and ( E )-4-hydroxy-3-(quinolin-2-yldiazenyl)-2 H -chromen-2-one (3CQD), were designed and synthesized using facile methods. The structures were validated through FTIR and NMR spectroscopy. The photophysical property analyses were further studied using UV-Vis and fluorescence spectrophotometers. Consequently, the absorption and emission spectra of 3CBD confirmed its selectivity of Hg 2+ and turn-off response to Fe 3+ . On the other hand, the absorption spectra analysis of 3CQD demonstrated selectivity in the presence of Hg 2+ . The colorimetric investigations demonstrated a significant visual response specifically for Hg 2+ , enabling real-time analysis in the corresponding solutions. The presence of other coexisting metal ions does not interfere with the detection of the target metal ion. The fluorescence studies of the two probes revealed that 3CBD was highly fluorescent, which was significantly quenched by Fe 3+ , upon excitation at 340 nm. Utilizing Job plot analyses, it was determined that the complexes 3CBD-Hg 2+ and 3CQD-Hg 2+ exhibit a binding stoichiometry of 1 : 1. The association constants for these complexes were measured to be 7.48 × 10 5 and 9.12 × 10 5 M -1 , respectively, indicating a strong association between both probes and their respective metal ions. Both chemosensors exhibited comparable limits of detection (LOD) and limits of quantification (LOQ) of 0.03 μM and 0.10 μM, respectively. Reversible studies confirmed that only chemosensor 3CQD could serve as a secondary sensor for EDTA. The theoretical studies calculated using Density Functional Theory (DFT) program at B3LYP/6-31G** (Spartan '10 package) level., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A naphthylthioic-based emissive probe (M) bearing a hydroxyl and amine group was designed and synthesized via a one-step Schiff base reaction process. The probe was characterized spectroscopically using 1 H NMR, UV-Vis and fluorescence spectrophotometers. The probe turned out to be spectroscopically and colorimetrically selective and sensitive to multiple cations and anions. Interestingly, the probe displayed characteristics of excited-state intramolecular proton transfer (ESIPT)-driven dual emissive channels; experiencing fluorescence enhancement upon the molar additions of Al 3+ as well as the anions used, events presumably ascribed to chelation fluorescence enhancement (CHEF), hydrogen bonding and deprotonation effects. Moreover, the fluorometric titration with Hg 2+ resulted in ratiometric spectral behaviors of M, with the disappearance of the peak at 450 nm, concomitant with the appearance of a new peak at 520 nm, distinguished by a clear isosbestic point, the same behaviors exhibited by Sn 2+ and Ag + analytes towards M. The introduction of all other cations used, resulted in fluorescence quenching, attributable to chelation enhanced fluorescence quenching (CHEQ), thereby inhibiting the ESIPT process. The experiments were all carried out in the aqueous environment medium of DMSO-H 2 O (9 : 1) at ambient temperature. Theoretical density functional theory calculations were carried out to gain insight into the interaction of M with cations and anions, and their influence on the HOMO-LUMO energy gaps., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Metal sulphides, including zinc sulphide (ZnS), are semiconductor photocatalysts that have been investigated for the photocatalytic degradation of organic pollutants as well as their activity during the hydrogen evolution reaction and water splitting. However, devising ZnS photocatalysts with a high overall quantum efficiency has been a challenge due to the rapid recombination rates of charge carriers. Various strategies, including the control of size and morphology of ZnS nanoparticles, have been proposed to overcome these drawbacks. In this work, ZnS samples with different morphologies were prepared from zinc and sulphur powders via a facile hydrothermal method by varying the amount of sodium borohydride used as a reducing agent. The structural properties of the ZnS nanoparticles were analysed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) techniques. All-electron hybrid density functional theory calculations were employed to elucidate the effect of sulphur and zinc vacancies occurring in the bulk as well as (220) surface on the overall electronic properties and absorption of ZnS. Considerable differences in the defect level positions were observed between the bulk and surface of ZnS while the adsorption of NaBH 4 was found to be highly favourable but without any significant effect on the band gap of ZnS. The photocatalytic activity of ZnS was evaluated for the degradation of rhodamine B dye under UV irradiation and hydrogen generation from water. The ZnS nanoparticles photo-catalytically degraded Rhodamine B dye effectively, with the sample containing 0.01 mol NaBH 4 being the most efficient. The samples also showed activity for hydrogen evolution, but with less H 2 produced compared to when untreated samples of ZnS were used. These findings suggest that ZnS nanoparticles are effective photocatalysts for the degradation of rhodamine B dyes as well as the hydrogen evolution, but rapid recombination of charge carriers remains a factor that needs future optimization., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Amakali, Živković, Warwick, Jones, Dunnill, Daniel, Uahengo, Mitchell, Dzade and de Leeuw.)