Ricinoleic Acid as a Green Alternative to Oleic Acid in the Synthesis of Doped Nanocrystals

Portrait of a UK-Africa Capacity Building Initiative Consortium 2015-2022: the Cameroon, Ghana, South Africa and United Kingdom Materials Initiative (CaGSUMI) for developing materials for solar cells

The CaGSUMI consortium was funded by the Royal Society-Department for International Development (later the Foreign, Commonwealth & Development Office) on the Africa Capacity Building Initiative programme between the years 2015 and 2022 and involved three Sub-Saharan African universities: Kwame Nkrumah University of Science and Technology, Kumasi, Ghana, University of Yaoundé I, Cameroon, and the University of Zululand, South Africa; and the University of Manchester in the United Kingdom. The project was used to cement an emergent UK-Africa network in the areas of materials chemistry related to renewable energy generation with both thin films and nanomaterials. The consortium's outputs led to numerous publications of African science in international journals, a number of graduated PhDs who went on to permanent academic positions and prestigious fellowships, the establishment of a capacity-building plan relevant to the chemistry departments in each of the African countries, and the installation of a number of first-in-kind pieces of kit for African laboratories that will keep them on a competitive footing at an international level for the next decade and more.

Growth Kinetics of Zinc Sulphide Nanocrystals Synthesized by Colloidal Thermolysis of Fatty Acid Carboxylates

Zinc sulphide (ZnS) is an important semiconductor with widespread electronic and catalytic applications. The growth kinetics of ZnS nanocrystals synthesized by the thermal decomposition of zinc ricinoleate carboxylates in an oleylamine:dodecanethiol (1 : 1) solvent mixture isreported. Crystalline sphalerite ZnS nanocrystals with quantum dot sizes of 2.3–5.3 nm were obtained at temperatures higher than 240°C. The p-XRD patterns showed a clear relationship between the crystallite sizes and the peak broadness at a temperature range of 250–300°C. The optical bandgap energies of the ZnS nanocrystals reduced from 4.27 eV to 3.73 eV as the time of reaction increased from 20 to 60 min at 250°C. The activation energy for the growth kinetics of the ZnS nanocrystals was determined to be 36.24 kJ/mol which compares closely to those reported in the literature for aqueous systems.