Synthesis and characterization of ZnO nanoparticles using pumpkin seed extract (Cucurbita moschata) by the sol-gel method

Pumpkin (Cucurbita moschata) is one of the easiest plants to grow in Indonesia. So far, pumpkin seeds have only been thrown away and become part of organic waste. Pumpkin seed extract has a functional group that can function as a reducing agent, stabilizer, and capping agent in the synthesis of nanoparticles ZnO by the sol-gel method. This study aims to test the ability of pumpkin seed extract in synthesizing ZnO nanoparticles using the sol-gel method. This research phase begins with the pumpkin seeds being dried and made into flour. Pumpkin seed flour was extracted and reacted with Zn(CH3COO)2. 2H2O as a precursor with variations in the concentration of the precursors, i.e. 0.05; 0.1; and 0.15 M at pH 8 with the addition of 0.1 M NaOH solution. The extract of pumpkin seeds was characterized using the Fourier Transform-Infrared (FTIR) instrument. ZnO nanoparticles were characterized using X-ray Diffraction (XRD) and Transmission Electron Microscope (TEM) instruments. FTIR results from pumpkin seed extract showed that there are hydroxy and carboxyl groups which allow them to act as reducing and stabilizing agents as well as capping agents in the synthesis process of ZnO nanoparticles. XRD results showed good crystallinity for each of the ZnO nanoparticles with a hexagonal crystal system. TEM morphology results identified that the nanoparticles obtained had a spherical shape and had a relatively uniform particle size distribution with an average particle size of 28.07 nm.