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Synthesis of copper oxide quantum dots: effect of surface modifiers

Copper oxide quantum dots were synthesized via precipitation process. Different surface modifiers (SMs) such as polyvinylpyrrolidone (PVP), Polyethylene glycol sorbitan monooleate (Tween 80) and Cetyltrimethylammonium bromide (CTAB) were used for modification of the size and shape of CuO nanoparticles. The effects of some parameters such as the type of surface modifiers on the band gap, structure and microstructure of samples were investigated. All samples showed quantum confinement behaviors such as band gap widening, the size less than the Bohr radius and the blue-shift of adsorption edge. The change of morphology from rod-like in the presence of Tween-80 to spindle shapes in CTAB one confirmed the strategic role of covering the surface of CuO particles by SMs. Moreover, CuO quantum dots with mean crystallite size of 2.3 nm and band gap of 2–2.5 eV were synthesized successfully. Furthermore, high degree of dispersion belonged to CuO nanoparticle synthesized by CTAB SM due to the maximum zeta potential value (28.1 mV at pH = 7.5).