Ntuli, T. D.; Sikeyi, L. L.; Mongwe, T. H.; Mkhari, O.; Coville, N. J.; Nxumalo, E. N.; Maubane-Nkadimeng, M. S. From Waste Cooking Oil to Oxygen-Rich Onion-Like Nanocarbons for the Removal of Hexavalent Chromium from Aqueous Solutions. S. Afr. J. Sci. 2023, 119.