The study of the green synthesis of Co3O4 nanomaterials and Co3O4/Ce24Co11/CeO2 nanocomposites using Kigelia pinnata fruit extract and their antibacterial potential

Abstract

In this study the aqueous extract of Kigelia pinnata fruit was used to produce three different nanomaterials; Co<inf>3</inf>O<inf>4</inf> (termed as KpCoO) NPs, Co<inf>3</inf>O<inf>4</inf>/Ce<inf>24</inf>Co<inf>11</inf>/CeO<inf>2</inf> (5 mol % Ce and 95 mol % Co, termed as KpCe@CoO-5) and Co<inf>3</inf>O<inf>4</inf>/Ce<inf>24</inf>Co<inf>11</inf>/CeO<inf>2</inf> (10 mol % Ce and 90 mol % Co, termed as KpCe@CoO-10) nanocomposites. A comparative examination of their antibacterial effectiveness against the harmful bacterial strains S. aureus and P. aeruginosa was conducted using KpCoO NPs and KpCe@CoO-5, KpCe@CoO-10 NCs. Optical and structural properties of the nanomaterials were determined using UV–visible, FTIR, XRD, SEM, EDX, HRTEM, BET and XPS spectroscopy. Crystallography Open Database (COD) and Match software were used to verify the presence of Co<inf>3</inf>O<inf>4</inf> and cerium mixed Co<inf>3</inf>O<inf>4</inf>/Ce<inf>24</inf>Co<inf>11</inf>/CeO<inf>2</inf> nanocomposites with the cubic, trigonal and cubic respectively. The fruit extract's phytochemicals played an important role in the formation as well as stabilization of nanomaterials with capping on the surface of the nanomaterials. The size of the nanomaterials and antibacterial activity are decreased by mixing the cerium salt mole% in copper salts. Overall, the used low-cost and environmentally benign green synthesized novel nanomaterials exhibited antibacterial activity of KpCoO in comparison to its nanocomposites (KpCe@CoO-5 and KpCe@CoO-10) with the Cerium metals. © 2024 Elsevier B.V.