green-prepared nickel oxide nanoparticles using cressa cretica leaf extract

In this work, we aimed to develop a simple and cheap procedure for the synthesis of nickel oxide nanoparticles (nio-nps) using aqueous cressa cretica (c. cretica) leaf extract as a green reducing and stabilizing agent and nickel nitrate hexahydrate as a nickel source [1]. in the present work, nio nanoparticles were synthesized through a simple sol–gel route in the presence of c. cretica leaf extract without any surfactant and reducing agent.the c. cretica plant leaves were washed thoroughly first with tap water to remove the adhering particles, then with distilled water. the purified c. cretica leaves were dried in shadow. the dried c. cretica leaves were crushed using mortar and pestle. the powdered c. cretica leaf was weighed (5.0 g) and mixed with 100 ml of distilled water. the mixture was stirred at 55 °c for 2 h and filtered and stored at 5 °c. after that, 30 ml of the plant extract solution was added to the 50 ml of 0.5m nickel (ii) nitrate hexahydrate (ni(no3)2.6h2o) solution, drop by drop. the solution was stirred for 5 h in a paraffin bath at a constant temperature of 72 °c. finally, at the plate's bottom, an extremely sticky, green-colored gel formed. the remaining product was dried for 4 h at 50 °c in an oven. then, the sediments were calcined at 500 °c for 2 h, yielding a black powder.also, nio-nps were identified by xrd, ft-ir, fesem, eds, uv-vis, zeta potential and tga/dta techniques. x-ray diffraction result revealed that the obtained product was nickel oxide with face-centered cubic structure. analysis of ftir spectra confirmed the composition of product. the result of thermogravimetric analysis of the precursor product showed that the proper calcination temperature was 500 °c. the results fesem and eds showed that nio-nps were pure with an average particle size of about 52 nm. nio-nps has zeta potentials of -19.1 mv at ph=7. the stability of produced particles in water is confirmed by this result [2].