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In a completely randomized design (CRD), 400 day-old Ross 308 broilers were randomly allotted to 5 diets with 0, 5, 10, 15 and 20% MSC, each with 8 replicates of 10. Weekly feed intake (FI), body weight gain (BWG) and feed conversion efficiency (FCE) were calculated whilst haemato-biochemistry was measured at d42. Overall, FI was linearly (P < 0.05) and quadratically (P < 0.01) decreased by MSC, of which the optimum inclusion was 15%, as BWG was linearly (P < 0.001) and quadratically (P < 0.05) decreased and FCE linearly decreased (P < 0.01) by MSC, of which the optimum dietary inclusion was 10%. Also, MSC linearly and quadratically decreased slaughter weight (P < 0.001 and P < 0.05, respectively), hot carcass weight (P < 0.001 and P < 0.05, respectively) and cold carcass weight (P < 0.001 and P < 0.05, respectively). Similarly, it linearly decreased white blood cells (P < 0.01) and lymphocytes (P < 0.05) as it linearly (P < 0.001) and quadratically (P < 0.01) decreased symmetric dimethylarginine (SDMA) and linearly (P < 0.001) increased serum cholesterol. In conclusion, up to 10% MSC can be incorporated into broiler diets in replacement of SBM without adverse effects.

NWU NatAgric Sciences: Research & Innovation

NWU NatAgric Sciences: Research & Innovation

MSc (Chemistry), North-West University, Mahikeng Campus In recent years, the development of efficient catalytic materials to degrade emerging contaminants in water has become a major research topic. This is due to an increased release of these types of contaminants into the environment and the inability of conventional technologies to remove them. Advanced oxidation processes (AOPs), which utilize generated reactive radicals to effect the degradation of molecules, have gained significant attention, not only because they can completely degrade emerging contaminants, but because they are environmentally friendly, cost-effective, and they have the potential mineralization of pollutants without generation of secondary waste. More attention is specifically focused on the use of semiconductor nanoparticles as catalysts for the generation of radical species in AOPs. Copper chalcogenides CuE (E = O, S) are promising semiconductor materials with various stoichiometric phases that influence their optical and structural properties. These stoichiometric phases are dependent on the methods of preparation, which, when meticulously manipulated, could be used to obtain a wide array of materials with varying properties. This dissertation demonstrated control over stoichiometric phases of Cu2-xS using copper(II)dithiocarbamate complex as a single- source precursor by varying reaction parameters such as type of capping agent used and reaction temperature. While for CuO nanoparticles, copper(II)acetate monohydrate was used as the single- source precursor at different calcination temperatures. Solvothermal decomposition of copper(II) dithiocarbamate complex in dodecanthiol(DDT) was used to prepare pure phase djuleite(Cu31S16) at 120 and 150 °C and roxbyite (Cu7S4) at 220 and 250 °C, while oleylamine was employed in the synthesis of pure phase CuS (covellite) at 120 °C and Cu9S5(degenite) at 220 °C. In between these two temperature extremes, mixed phases were obtained that were not subjected to further characterization. Copper oxide nanoparticles were prepared via the thermal decomposition of copper(II)acetate monohydrate at three different temperatures, which were informed by the decomposition profile of the complex when analyzed by thermogravimetric analysis. The as- prepared pure phase copper chalcogenide nanoparticles were further characterized using scanning electron microscope (SEM), transmission electron microscope (TEM), and UV-visible absorption spectroscopy. The morphologies of the copper sulfides varied from pseudo spherical to spherical, and it was interesting to observe the digenite displayed rod shape morphology despite being prepared from the same precursor compound. The copper sulfide samples were used as photocatalysts to degrade tetracycline (TC) as model antibiotics under visible light irradiation. The results of the study showed varying degradation efficiencies with Cu7S4 (250 °C) exhibiting the best activity in the reaction system of up to 99% within 120 min of light exposure, compared to CuS, Cu9S5, Cu31S16 (120 °C), Cu31S16 (150 °C) and (Cu7S4 (220 °C) which degraded 88, 98.5, 46.5, 85 and 90 % respectively under the same conditions. The copper oxides of pure phases, obtained at 350 and 400 °C, labeled as CuO (350°C) and CuO (400 °C), respectively, were used to degrade acyclovir (ACV) as model antiviral. Both samples (CuO at 350°C and CuO at 400 °C) demonstrated high and comparable removal efficiency of 96.61 and 99.55 %, respectively, after 120 min. The results of this study confirm the potential of copper chalcogenides as semiconductor catalysts for the degradation of pharmaceuticals from an aqueous solution. In addition, the results showed that the phase of the chalcogenide affects the degradation efficiency. Masters

MSc (Animal Science), North-West University, Mahikeng Campus The high costs of conventional protein sources such as soya bean meal (SBM) have prompted the search for a cheaper alternative and readily available protein sources like marula seed cake (MSC) for pig production, particularly by smallholder farmers in Southern Africa. Marula seed cake (MSC) has a high crude protein and amino acid content similarly to SBM. Due to its high content of protein and residual oil, both of which provide ideal conditions for the growth and proliferation of toxigenic fungi, MSC is however naturally contaminated with mycotoxins. Mycotoxins are known to induce deleterious effects and cause economic losses in pigs by causing reduced growth, immunosuppression and other effects. Hence the need to find strategies to counter their deleterious effects in pigs fed MSC-supplemented diets. This study was aimed at investigating ameliorative effects of T. violacea bulb extract bio-fabricated zinc oxide (ZnO) nanoparticles (Nano-ZnO) in piglets fed diets supplemented with naturally mycotoxin-contaminated MSC. Nano-ZnO was phyto-synthesized using the aqueous leaf extract of T. violacea as reducing and stabilizing agent. The synthesized ZnO NPs were characterized by techniques including X-ray diffraction (XRD), UV–visible spectroscopy, transmission electron microscopy (TEM), and scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) spectrometer. The morphological studies confirmed that the as-prepared ZnO NPs were spherical, with an average particle diameter of 45.26 nm. The PXRD pattern indicated single-phase hexagonal ZnO NPs with high crystallinity, while the absorption spectra showed evidence of quantum size effect. The Nano-ZnO were applied in a piglet feeding trial by orally administering (gavaging) them to piglets fed diets supplemented with naturally-mycotoxin contaminated MSC. A total of 60, 4-week old weaned Large White piglets were randomly allocated to two (2) iso-energetic and iso-nitrogenous diets formulated by replacing SBM (Control; 0% MSC) (Group A) with MSC (Treatment; 20% MSC) (Group B). Once-daily, Group A piglets (0% MSC) were orally drenched with 10 mL of the vehicle (25% ethanol in water; 25 parts ethanol: 75 parts water, v/v) whilst Group B piglets (20% MSC) were similarly orally drenched with an equivalent volume of the: vehicle (25% ethanol) (Group B1), 50 mg/L of bulk ZnO in 25% ethanol (Group B2), 50 mg/L of chemically-synthesised Nano-ZnO in 25% ethanol (Group B3), and 50 mg/L of green (T. violacea bulb extract-fabricated) Nano-ZnO in 25% ethanol (Group B4). Average feed intake (FI) and body weight gain (BWG) were measured weekly, and then feed conversion efficiency (FCE) was calculated by dividing the BWG by the FI. On day 33, blood was collected for serum analysis, and all animals were slaughtered after which carcass and meat quality measurements were taken. The ... Masters

PhD (Chemistry), North-West University, Mahikeng Campus The development of effective ternary metal sulfides supported graphene oxide composites as catalytic materials have been explored in this thesis. The Single source precursor method employing dithiocarbamate metal complexes were employed as precursor in a heat-up method in the synthesis of the copper-based ternary metal sulphides, which were composited with graphene derivatives through facile techniques. The suitability of the metal complexes as single source precursors was firstly evaluated by exploring the obtained metal complexes as precursors for the synthesis of their respective binary metal sulphides. Particularly, the ability to obtain different CuxS phases, which is important for the selective synthesis of different stoichiometric phases of Cu-M-S was explored. Thermolysis of copper bis dithiocarbamate metal complex in a mixture of oleylamine (OLA) and dodecanethiol (DDT) showed a mixture of phases were obtained at relatively low temperature with pure phase of Cu5S9 only obtainable at high temperature. This study showed the significance of solvent property in influencing phase selectivity in the synthesis of Cu2-xS. The thermolysis of bismuth(III) tris (N-methyl-N-phenyl dithiocarbamate) complex was also explore in a solvent mixture oleylamine, dodecanethiol and octadecene. At temperature range of 150 -250 °C Bi2S3 nanoparticles with varying microstructural properties was obtained. The microstructural properties of the nanoparticles were explored using the Scherrer equation, Williamson-Hall plot and Rietveld analysis. A close agreement between the models was observed with the particle size ranging between 20.1 – 45.9, 20.9 -26.6 and 23.0-29.7 nm for the Scherrer equation, Williamson-Hall’s plot and Rietveld analysis respectively. Similarly, antimony(III) tris (N-methyl-N-phenyl dithiocarbamate) complex was thermolyzed in hexadecylamine solvent and the microstructural property was studied. In addition to the microstructural studies, other crystal properties and empirical parameters such as lattice parameters, cell volume, bulk density, X-ray density, surface area and porosity were evaluated. The particle size for the Sb2S3 nanoparticles obtained ranged between 85.1-111.3 nm for the explored models, while all the models affirmed the strain in the strain to be in the lattice to be due to lattice contraction. The empirical analysis showed the presence of Sb vacancies, while the lattice parameters and other cell parameters agreed significantly with values in literature. After establishing the thermal decomposition products of these complexes, they were co-thermolyzed with other precursor compounds which have comparable decomposition profiles for the synthesis of ternary Cu-M-S. Firstly, the selective synthesis of two phases of copper tin sulphides: petrukite (Cu3SnS4) and kuramite (Cu2SnS3), was achieved by the solvothermal decomposition of diphenyl tin(II) dithiocarbamate and Cu (II) bis N-methyl-N-phenyl dithiocarbamate complex by the heat-up process in high boiling solvents. Cu2SnS3 was obtained in oleylamine at 220 °C, while Cu3SnS4 was obtained in a mixture of oleylamine and dodecanethiol at 180 °C. The particle size distribution was 13.7 ± 2.4 for Cu2SnS3 and 11.3 ± 1.5 nm for Cu3SnS4, with the band gap energy being 1.16 and 1.57 for Cu2SnS3 and Cu3SnS4 respectively. The photoluminescence spectroscopy measurement showed a lower charge carrier recombination in Cu2SnS3 compared to Cu3SnS4, which account for the 94.0% degradation efficiency towards Tetracycline degradation compare to 73.0% recorded for Cu3SnS4. Electrochemical measurements also showed that Cu2SnS3 exhibited lower resistance, getter charge transport and conducting properties compare to Cu3SnS4. Subsequently, supported Cu2SnS3 and Cu3SnS4 nanoparticles were synthesized through facile solvothermal processes. Cu2SnS3 supported by reduced graphene oxide (rGO) were prepared at different rGO ratio 0-20%. The photocatalytic activity of the nanoparticles for tetracycline degradation was influenced by the weight fraction of rGO, with composite with 20% rGO composition showing the maximum degradation efficiency of 93% compared to compared to 64, 65.5 and 68.8% degradation recorded for 0, 5, and 10% rGO composition respectively. rGO was observed to improve the degradation efficiency by enhancing the adsorption capacity of the nanoparticle and also reducing charge carrier recombination. For the Cu3SnS4 phase, the influence of graphene oxide (GO), protonated graphitic carbon nitride (PCN) and composite of GO and PCN (GO/PCN) on the degradation of tetracycline was explored. The study showed that the composite GO/PCN showed the highest degradation efficiency of 96.5% compare to 85.2 and 90.9% recorded for composites with PCN and GO respectively. The enhanced activity of the GO/PCN based composite was found to be due to exciton generation and enhanced adsorption property. Afterwards, selective synthesis of copper antimony sulphides (CAS) was explored. Three different phases of CAS were obtained: chalcostibite (CuSbS2), famantinite (Cu3SbS4) and tetrahedrite (Cu12Sb4S13) using copper(II) dithiocarbamate and antimony(III) dithiocarbamate complexes in a solvothermal heat-up process. The catalytic activity of the three phases for persulfate activation of tetracycline degradation was explored with degradation efficiencies of 26.1, 54.6 and 55.6% achieved by CuSbS2, Cu12Sb4S13 and Cu3SbS4 respectively. The study of the influence of pH on the persulfate activation process showed a higher efficiency of 85.5% was achieved under neutral condition. Radical scavenging experiment showed the process was radical based process, with the initiation being a one electron transfer process. the Cu3SbS4 phase with tetrahedrite phase exhibiting the highest activity. Further study on improving the activity of CuSbS2 was explored by supporting the nanoparticle on graphene oxide. The supported CuSbS2 was then explored in the degradation of tetracycline in persulfate activation and photocatalytic processes. The percentage degradation was 94 and 74% for the photocatalytic and persulfate activation process respectively. Mechanism study showed that the photocatalytic process proceeded significantly through the activity of photogenerated holes while the persulfate activation process, was a non-radical process. Finally, the selective synthesis of copper bismuth sulphide (CBS) phase was attempted using Bi(III) bis N-methyl-N-phenyl dithiocarbamate and Cu(III) bis N-methyl-N-phenyl dithiocarbamate as single source precursors. However, only the wittichenite phase (Cu3BiS3) was obtained in pure phase. The Cu3BiS3 nanoparticles was agglomerated and oval-shaped with a particle size of 60.1 nm. The obtained semiconductor nanoparticle was further supported on reduced graphene oxide and explored as a catalyst in UV-light assisted persulfate activation process and in a photocatalytic process for the degradation of diclofenac. A degradation efficiency of 74% was achieved in the photocatalytic process, while the UV-light assisted persulfate activation process attained 84% degradation efficiency. The composites showed great capacity for degradation for the degradation of a wide variety of pollutant with 100% degradation efficiency achieved for methyl orange, tetracycline and methylene blue, while bisphenol reached 81% efficiency. The study showed that the nanocomposite exhibited a higher activity in the UV-light assisted process, with the process showing lower energy consumption when compared to other reported process. The results of this study confirm the potential of dithiocarbamate complexes as precursor compounds for achieving phase selectivity synthesis of Cu-M-S semiconductors and also, the potential of these materials as versatile catalysts for advanced oxidation processes. In addition, the study has shown that graphene oxide/reduced graphene oxide is a suitable support material for enhancing the catalytic activity of these semiconductors. Doctoral

PhD (Chemistry), North-West University, Mafikeng Campus, 2019 Organotin(IV)dithiocarbamate owe their functionality and usefulness to the individual attributes of the organotin and the dithiocarbamate moieties. The synergy exhibited by these moieties has resulted in the enhanced biological activity of the hybrid molecule. This thesis reports the synthesis, characterization and evaluation of the biological properties (including antimicrobial, antioxidant an~ anticancer activities) of series of organotin(IV) dithiocarbamate complexes. Organotin(IV) chlorides of various alky and aryl groups [RnSnCl4_n] (n = 1, 2; R = CH3, C4H9, C6Hs) were utilized, while the dithiocarbamate ligands [-S2CNRR'] (R= H, CH3, C2H5, C4H9, C3Hs and R'= C6Hs, C6Hs-CH2, CH3-C6Hs, C2Hs-C6Hs, C3Hs) were constituted of different alkyl, allyl and aryl substituents, resulting in array of compounds with different stereochemistry. All the complexes were characterized using spectroscopic techniques (FTIR, 1H and 13C and 119Sn NMR) and elemental analysis, and a few of them were further characterized by single crystal X-ray diffraction. The thermal decomposition properties of the complexes were studied using thermogravimetric analyser, and they displayed varying decomposition patterns to give tin sulfide residue of different phases. The antimicrobial properties of the complexes were studied using some gram positive bacteria (Bacillus cereus and Staphylococcus aureus), gram negative bacteria (Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa) and some fungi (Candida albicans and Aspergillus jlavus). They showed great potential as antimicrobial agents better than their respective ligands, and compared favorably with other standard drugs used as control. The complexes also exhibited potentials as antioxidant agents from the study carried out using 2,2-diphenyl-l-picrylhydrazyl (DPPH) and reducing power assays methods. Furthermore, the preliminary in vitro cytotoxicity activity study of the complexes was tested against tumor cell line human cervix carcinoma (HeLa). Activity ranged from very good to moderate, for all tested complexes. These complexes could be useful lead compounds m antibiotic, antioxidant and anticancer studies. Doctoral

MSc (Applied Chemistry), North-West University, Mahikeng Campus The field of nanoscience cuts across many areas of research and researchers continue to explore this interesting area, with the objective of developing materials or improving the properties of the existing ones. Nanomaterials have promising applications in electronics, agriculture, medicine, photo devices and environment. Phytonanotechnology which involves the use of plants has carved out an interesting niche in the field of nanoscience making most Indian greeneries and spices important substrates for the synthesis of nanoparticles (NPs). Umbrella plant, Welsh onion and Guar plants were used for the synthesis of silver NPs in this work. The aqueous plant extract and different concentrations ( 1 mM, 2 mM and 5 mM) of the precursor compound (AgNO3) were prepared. In the synthesis of the NPs, two volume ratios of I :5 and 1: IO of the substrate to the precursor were made from each of the precursor (AgNO3) concentration (I mM, 2 mM and 5 mM), and the rate of formation of silver NPs was monitored using UV-vis spectroscopy. The biosynthesized NPs which were represented as UmAgNPs, WoAgNPs and GuAgNPs (reflecting the type of plants involved in their synthesis: Umbrella plant, Welsh onion and Guar plants respectively) were further characterized using Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and powder X-ray diffraction (pXRD) techniques. The results of the FTIR analysis revealed the presence of biomolecules such as sugars, amino acids, flavonoids on the surface of the NPs, therefore confirming the role of the plants extracts as passivating/capping agents in addition to their reducing effect. The particle sizes of all the NPs: UmAgNPs. WoAgNPs and GuAgNPs, were below 20 nm. with the NPs synthesized from I mM AgNO3 using Welsh onion plant (WoAgNPs) showing the highest average particle size of 15.72 nm. Averagely, GuAgNPs obtained from 2 mM AgNO3 using I : 10 volume ratio has the lowest particle size among all. However, particles mediated by umbrella plant (UmAgNPs) and prepared from 2 mM AgNO3 using both of I :5 and I: 10 volume ratio gave the most stable NPs with high degree of monodispersity. The potential application of the green synthesized silver NPs in the treatment of water polluted with organic dyes was evaluated by studying their ability to photo-catalytically degrade methyl red, and their antimicrobial potency against some bacteria (majorly the water borne). The U mAgNPs showed the greatest percentage of degradation of about 29. 72%. The antimicrobial properties of the NPs against common microbes: Staphylocucus auerus, Bacillus cerues, Kleb. pneumonia and Echerichia coli displayed interesting results with WoAgNPs having the greatest growth inhibition against the studied microbes. Masters