Facile green synthesis of lanthanum oxide nanoparticles using Centella Asiatica and Tridax plants: Photocatalytic, electrochemical sensor and antimicrobial studies
B.N. Rashmi, Sujatha F. Harlapur, K. Gurushantha, C.R. Ravikumar, M.R. Anil Kumar, M.S. Santosh, V.G. Dileep Kumar, A. Naveen Kumar, Abdul Kalam Azad, H. C. Ananda Murthy
Abstract
Lanthanum oxide (La2O3) nanoparticles (NPs) were prepared by the facile green combustion method using the leaf powders of Centella asiatica and Tridax plants (C-La2O3 and T-La2O3 NPs). Various analytical and electrochemical techniques were employed to understand the morphology, crystallinity, and band gap of La2O3 NPs. X-ray diffraction (XRD) studies revealed that the NPs exists in a hexagonal crystal structure with a crystallite size of 20 nm. The morphological studies (SEM and TEM) revealed La2O3 clusters with porous structures. UV-DRS (diffuse reflectance) spectra was used to arrive at the band gap of 5.44 eV and 5.61 eV for C-La2O3 and T-La2O3 NPs. The thermogravimetric studies showed a 2-step decomposition process involving La(OH)3. Electrochemical and photocatalytic studies were conducted to explore the efficiency of C-La2O3 and T-La2O3 NPs. The better photocatalytic degradation was observed for T-La2O3 NPs with 60% efficiency. In addition, La2O3 NPs also exhibited good antimicrobial activities.