{'fraction_non_alphanumeric': 0.024485798237022526, 'fraction_numerical': 0.01028403525954946, 'mean_word_length': 5.364485981308412, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Synthesis of cerium oxide nanoparticles using Vitex extract

The aim of this work was to study composition and antioxidant/reducing properties of Vitex cannabifolia leaves extract and to characterize it as a possible active agent for green synthesis of cerium oxide nanoparticles (CeO2-NPs). The aim of the study was also to prepare CeO2-NPs and to investigate the particles sizes, texture and morphology. Antioxidant/reducing properties of Vitex cannabifolia leaves extract were studied using Folin-Chiocalteu and 2,2-diphenyl-1-picrylhydrazyl (DPPH) tests, composition of the extract was explored by means of laser desorption/ionization time-of-flight mass spectrometry method. The extract was found to possess very high antioxidant/reducing capability, showing fast reduction of DPPH radicals even at 100-fold dilution. The main components of the extract were phenolic acids, flavonoids and terpenes; all these compounds are known to be active reducing and/ or stabilizing agents in green synthesis of various nanoparticles. Using the extract, CeO2-NPs were prepared by means of the procedure that included the reduction of cerium(IV) ammonium nitrate by extract components followed by annealing the precipitate at 600 °C under in air conditions. The particles synthesized were characterized by means of scanning electron microscopy, X-ray diffraction and nitrogen adsorption methods. According to X-ray diffraction and electron microscopy data, CeO2-NPs had crystalline structure, spherical form and fairly uniform particles size distribution; surface area of the particles was estimated from nitrogen adsorption isotherms as about 30 m2 per 1 g. The average crystallite size determined from X-ray line broadening data was about 17 nm, the average particles diameter derived from surface area data was up to ~30 nm. Thus, one can conclude that the particles synthesized are small enough to be suitable for biomedical applications while Vitex cannabifolia extract is the effective reagent for green synthesis of cerium oxide nanoparticles.