Materials Science and Engineering B 290 (2023) 116275 0921-5107/© 2023 Elsevier B.V. All rights reserved. Effcient adsorption and antimicrobial application of bio-synthesized porous CeO 2 nanoparticles Sthitiprajna Muduli a , Saroj Sekhar Behera b , Ranjan Kumar Mohapatra c , Pankaj Kumar Parhi d, * , Tapas Ranjan Sahoo a, * a Department of Chemistry, School of Applied Sciences, KIIT Deemed to be University, Bhubaneswar, Odisha, India b Hydro- and Electro-Metallurgy Division, CSIR-Institute of Minerals and Materials Technology (IMMT), Bhubaneswar, Odisha, India c School of Chemical Technology and School of Biotechnology, KIIT Deemed University, Bhubaneswar, Odisha, India d Department of Chemistry, Fakir Mohan (F.M.) University, Vyasa Vihar, Nuapadhi, Balasore, Odisha, India A R T I C L E INFO Keywords: CeO 2 NPs Green Synthesis Reactive blue adsorption Antimicrobial application ABSTRACT The present research demonstrates the green synthesis of CeO 2 nanoparticles (NPs) using the Acacia Concinna fruit extract by sol–gel route. The synthesized CeO 2 NPs are applied for the adsorptive removal of Reactive Blue (RB) azo dye and antimicrobial activities. The CeO 2 NPs are characterized using different techniques e.g. X-ray Diffraction Spectroscopy (XRD), Fourier-Transform Infrared Spectroscopy (FT-IR), UV–vis Spectroscopy, Scan- ning Electron Microscope (SEM), High Resolution Transmission Electron Microscopy (HR-TEM), Dynamic Light Scattering (DLS), Raman Spectroscopy, etc. The structural investigations (XRD) reveal the single-phase cubic fuorite-type structure of CeO 2 with 22.7 nm of crystallite size. The spectral analysis (FTIR) shows a strong vi- bration band below 849 cm 1 owing to Ce-O-Ce stretching vibrations. A porous network-like morphology of the CeO 2 NPs is observed by SEM, where HR-TEM micrographs reveal that the nanoparticles are roughly spherical in nature. Raman spectroscopy confrms the vibrational mode of the cubic fuorite type structure of CeO 2 NPs at 462 cm 1 . The maximum loading capacity of CeO 2 NPS is 188.67 mg/g. The antibacterial activity of the CeO 2 NPs is evaluated against S. pneumoniae and E.coli, which shows 96.17 % and 96.89 % growth inhibition at 20 mg/ l. 1. Introduction Last few decades, nanotechnology has been a rousing research entity in material science. The release of dye effuents from various industries dealing with food, plastic, textiles, and pharmaceuticals poses a serious threat to the environment [1]. The high toxicity and signifcant pollu- tion problems caused by the dyes are well known. Because of the discharge of dye effuents into water bodies, de-oxygenation capacity decreases, which can impede sunlight infltration and harm aquatic life. Furthermore these dye effuents are extremely hazardous to humans. As a result, it is critical to remove dyes from water bodies, and there are several methods for doing so, including adsorption, biodegradation, chemical, electrochemical, photochemical, and ultrafltration methods etc. [2]. Dye effuents are chemically very stable and are relatively resistant to physicochemical methods [3]. Although biodegradable dye degradation techniques are cost-effective, they are slow and ineffective. That’s why, among all accessible dye removal techniques, adsorption was observed to be the most benefcial and least expensive [4]. When comparing nanoparticles to traditional adsorbent materials like acti- vated alumina, silica gel, zeolites, and polymeric adsorbents etc., it was evident that nanoparticles as an adsorbent have far higher effciency and can remove contaminants and impurities much faster [5,6]. Nanotech- nology have also emerged as a viable alternative to traditional water purifcation methods in recent decades. Metal oxide nanoparticles are smaller in size and possess higher surface area to volume ratio that contributed to their effciency as a great adsorbent material [7,8]. Metal oxide nanoparticles, e.g. ZnO, TiO 2 , SnO 2 , MnO 2, CeO 2, etc. are emerging as a potential option for adsorption of dyes. The toxicity of dyes gets affected by the physicochemical properties of nanomaterials such as shape, size, chemical composition and physiochemical stability [9,10]. Specifc optical characteristics such as UV absorption, color ab- sorption in the visible region and photoluminescence are exhibited by metal oxide nanoparticles [11,12]. The electrical properties of Semi- conductors and metallic nanomaterials results in their electrical con- ductivity and electrochemical properties [13]. Among all, CeO 2 NPs have immense substantial properties that are * Corresponding authors. Contents lists available at ScienceDirect Materials Science & Engineering B journal homepage: www.elsevier.com/locate/mseb https://doi.org/10.1016/j.mseb.2023.116275 Received 13 June 2022; Received in revised form 31 December 2022; Accepted 10 January 2023