Photocatalytic degradation of dyes, pharmaceutical and the removal bacterial pollutants using Rod shaped green derived CuO nanoparticles

Abstract

ABSTRACT Water pollution caused by the textile industry, increased antibiotic usage and natural pollutants has been on the rise in the last decades; hence, there is a need to find multifunctional and environmentally safe materials. In this study, we report on the facile and biosafe route for the synthesis of CuO nanoparticles using Monsonia Burkeana plant. This material was characterised using HRTEM, HRSEM, EDS, SAED, XRD, FTIR and UV-vis. The CuO nanoparticles were further tested for their photocatalytic and antibacterial activity against methylene blue (MB), malachite green (MG), sulfamethoxazole (SMX), E.coli and S.aureus, respectively. FTIR and UV-vis confirmed the formation of these materials and the deposition of the plant phytochemicals on the materials. XRD and EDS further corroborated this formation through peak identification. Through HRSEM and HRTEM, a rod-like morphology was identified and from image J measurements, they were found to be between 10 and 50 nm in particle size. Testing their photocatalytic activity against dyes, the highest degradation was achieved against MB at 83%. Reusability and trapping studies were also conducted where it was shown that the electrons were species responsible for the degradation of MB. For SMX, the degradation was pH dependent whereby at pH 7, the highest degradation of 58% was achieved. As an antibacterial agent, the green CuO was more active against E.coli and produced a complete removal (100%) using the highest concentration of 0.05 mg/ml. These results confirm that these green derived materials can be used for the treatment of various pollutants. Furthermore, their recent use in pharmaceutical degradation of antibiotics found in water will greatly assist in curbing the rise in the current emerging pollutants.