https://ir.unisa.ac.za/handle/10500/21138 2026-05-11T20:11:03Z 2026-05-11T20:11:03Z Moutloali, Richard Motlhaletsi https://ir.unisa.ac.za/handle/10500/31145 2025-02-20T06:48:35Z 2023-08-22T00:00:00Z

Chemistry : a critical foundation in quality water provision Moutloali, Richard Motlhaletsi

2023-08-22T00:00:00Z Moloto, Makwena Justice https://ir.unisa.ac.za/handle/10500/31144 2025-02-20T06:47:50Z 2022-11-21T00:00:00Z

Realities of fabricating nanomaterials: past, present and future prospects Moloto, Makwena Justice

2022-11-21T00:00:00Z Fito, Jemal Abewaa, Mikiyas Nkambule, Thabo https://ir.unisa.ac.za/handle/10500/29832 2023-06-13T09:59:15Z 2023-02-09T00:00:00Z

Magnetite-impregnated biochar of parthenium hysterophorus for adsorption of Cr(VI) from tannery industrial wastewater Fito, Jemal; Abewaa, Mikiyas; Nkambule, Thabo Abstract The tannery industry inevitably generates toxic and catastrophic wastewater, which results in a huge threat to public health and water resources. Therefore, this work aimed to synthesize parthenium hysterophorus-based biochar–Fe3O4 composite for removal of Cr(VI) from tannery wastewater under 34 full factorial experimental designs of the Box–Behnken, which was analyzed using response surface methodology under four independent factors of pH (3, 6, and 9), initial Cr(VI) concentrations (40, 70, and 100 mg/L), contact times (30, 60, and 90 min), and adsorbent doses (20, 60, and 100 mg/100 mL). This composite adsorbent was described by a high BET surface area of 237.4 m2/g, XRD prominent peaks, SEM morphology corroborate and FTIR multifunctionalities of O–H at 3296 cm−1, the vibration of ketone C–OH at 1240 cm−1, and the vibration of C–O–C at 1147 cm−1 and Fe–O stretching at 542 cm−1. The maximum Cr(IV) removal efficiency of 91.8% was recorded at an initial Cr(VI) concentration of 40 mg/L, pH of 3, adsorbent dose of 100 mg/100 mL, and a contact time of 90 min, whereas the minimum Cr(VI) removal of 17.3% was observed at an initial Cr(VI) concentration of 100 mg/L, 20 mg/100 mL of adsorbent dose, pH of 9, and contact time of 30 min. The concentration of Cr(VI) in real wastewater was determined to be 85.13 mg/L and its remediation was found to be 81.8%. Langmuir’s model was the best fit with experimental data at R2 0.99 and qmax 400 mg/g, showing that the adsorption process was homogenous and monolayer. In conclusion, the adsorption results were encouraging, and biochar–Fe3O4 appears to be a potential candidate for Cr removal from wastewater.

2023-02-09T00:00:00Z Shi, Bao Li, La Chen, Aibing Jen, Tien-Chien Liu, Xinying Shen, Guozhen https://ir.unisa.ac.za/handle/10500/28421 2022-03-31T10:58:44Z 2021-12-15T00:00:00Z

Continuous Fabrication of Ti3C2Tx MXene-Based Braided Coaxial Zinc-Ion Hybrid Supercapacitors with Improved Performance Shi, Bao; Li, La; Chen, Aibing; Jen, Tien-Chien; Liu, Xinying; Shen, Guozhen Highlights Ti3C2Tx MXene-based coaxial zinc-ion hybrid fiber supercapacitors (FSCs) were fabricated with braided structure, which can be prepared continuously and present excellent flexibility and ultrastability. A sports watch driven by the watch belts which weaved uses the obtained zinc-ion hybrid FSC and LED arrays lighted by the FSCs under embedding into textiles, demonstrating the great potential application in smart wearable textiles. Abstract Zinc-ion hybrid fiber supercapacitors (FSCs) are promising energy storages for wearable electronics owing to their high energy density, good flexibility, and weavability. However, it is still a critical challenge to optimize the structure of the designed FSC to improve energy density and realize the continuous fabrication of super-long FSCs. Herein, we propose a braided coaxial zinc-ion hybrid FSC with several meters of Ti3C2Tx MXene cathode as core electrodes, and shell zinc fiber anode was braided on the surface of the Ti3C2Tx MXene fibers across the solid electrolytes. According to the simulated results using ANSYS Maxwell software, the braided structures revealed a higher capacitance compared to the spring-like structures. The resulting FSCs exhibited a high areal capacitance of 214 mF cm–2, the energy density of 42.8 μWh cm−2 at 5 mV s−1, and excellent cycling stability with 83.58% capacity retention after 5000 cycles. The coaxial FSC was tied several kinds of knots, proving a shape-controllable fiber energy storage. Furthermore, the knitted FSC showed superior stability and weavability, which can be woven into watch belts or embedded into textiles to power smart watches and LED arrays for a few days.

2021-12-15T00:00:00Z