Green synthesis of Co₃O₄ nanoparticles using Euphorbia heterophylla L. leaves extract: characterization and photocatalytic activity

In this research, C0₃O₄ NPs were prepared by green synthesis method using Euphorbia heterophylla L. leaves extract (ELE). ELE contains secondary metabolite compounds like alkaloid, as weak base source, and saponin, as capping agent, in the synthesis of Co₃O₄ nanoparticles. The Fourier-Transform Infrared (FTIR) spectrum of ELE depicted some peaks at 3245, 1610 and 1071 cm⁻¹ which represented hydroxyl group, carbonyl group (C=O) and C-N group, respectively. Co₃O₄ NPs were characterized by FTIR Spectrometry, UV-Vis Spectroscopy, Particle Size Analyser (PSA), X-Ray Diffraction (XRD) and UV-Vis DRS. The FT-IR results showed the presence of Co (II)-O bond and Co (III)-O bond at the wavenumber of 574 and 699 cm⁻¹, respectively. UV-Vis characterization spectroscopy indicated the typical peak of Co₃O₄ NPs found at the range wavelength of 200-350 nm and 380-600. The particle size of Co₃O₄ NPs was 69.75 nm confirmed by Particle Size Analyser. XRD characterization showed that Co₃O₄ NPs had diffraction peaks at 31.1953°; 38.5401°; 44.8076°; 50.2027°; 59.2743° and 65.1419°. The band gap energy of CosO4 NPs was 1.53 eV confirmed by UV-Vis DRS. TEM image showed that morphology of Co₃O₄ NPs was spherical shaped with the particle size of ∼17 nm. Co₃O₄ NPs had a photocatalytic activity in the degradation of methylene blue about 63.105% for 3 hours.