Synthesis and characterization of nanosize copper oxide by non-aqueous sol–gel process

Copper oxide nanoparticles calcined at temperatures varying from 500 to 900 °C were prepared through non-aqueous sol–gel route by using 2-ethyl hexanol as a modifying agent. Phase composition, presence of functional groups, thermal behavior, surface morphology and elemental composition of the prepared samples were identified by XRD, IR, TGA, FESEM and EDX. The results revealed the formation of single phase, i.e., monoclinic tenorite copper oxide with its entire transformation after calcination at 500 °C. Polyhedron shape nanoparticles of size below 100 nm were formed with a significant increase in the particle size and agglomeration due to nucleation growth of nanoparticles with the rise in calcination temperature. The synthesized samples showed a direct band gap of 4.08–4.14 eV. The study revealed that following the non-aqueous sol–gel process with 2-ethyl hexanol as a modifying agent inhibited agglomeration resulting in the formation of well-dispersed nanoparticles.