Blue Shift in the Oriented Cuprous Oxide Micro Structures Prepared via PEG-400 as the Soft Template by γ-Irradiation

Abstract

Cuprous oxide (Cu₂O) crystals with platelates structures were synthesized via γ-irradiation reducing reaction under ambient conditions, the polyethylene glycol-400 (PEG-400) as nonionized surfactant and ethylenediamine tetraacetic acid disodium salt (Na₂EDTA) as chelator of Cu²⁺ ions. XRD and FESEM were used to illustrate Cu₂O crystals with platelates structures. The products were also been characterized by HRTEM, ED analysis and UV-VIS absorption spectrum. All the results indicated that the Cu₂O crystals with platelates were successfully prepared under γ-irradiation. The possible mechanism is that the existence of EDTA ions and polyethylene glycol may make growth rate along the <111> direction far exceeding that of the <100> direction, leading to the formation of platelate structure Cu₂O at last. Its UV-VIS absorption peak revealed blue shift phenomena, with the corresponding band gap of 2.25 eV, the size effect resulted in an obvious blue shift.