Effect of Cu+ ions on the structure, morphology, optical and photocatalytic properties of nanostructured ZnO

Solid solutions Zn 1−x Cu x O and/or hybrid materials Zn 1−x Cu x O/Cu x O of the “core-shell” type were obtained by one-step thermolysis of Zn 1−х Cu x (HCOO)(OCH 2 CH 2 O) 1/2 complexes. Precursors the Zn 1−х Cu x (HCOO)(OCH 2 CH 2 O) 1/2 complexes were synthesized under solvothermal method from the corresponding formates and ethylene glycol. It was established that copper in these materials is a promoter of the photoactivity and morphology of aggregates. Zn 1−x Cu x O solid solutions (0 < x < 1) have 1D-morphology of aggregates, Zn 1−x Cu x O/Cu x O hybrid materials are spherical. According to TEM, XPS, optical spectroscopy and voltammetry data, Cu + prevails in the solid solution samples and its concentration increases with transition to hybrid materials. It was shown that solid solutions with tubular particle morphology exhibit the maximum photoactivity of As 3+ in UV and blue light. The expansion of the spectral range of Zn 1−x Cu x O irradiation to the visible region is explained by the formation of acceptor levels (Cu 2+ + e − → Cu + /V O + + e − → V O ) in the band gap of ZnO, which increases the efficiency of separation of photogenerated electron-hole pairs. The presence of Cu + in the material intensify photoactivity due to the formation of an overactive oxygen radical O 2 − . • Novel one step synthesis of Zn 1−x Cu x O/Cu x O by thermolysis of Zn 1−х Cu x (HCOO)(OCH 2 CH 2 O) 1/2 was used • Cu concent determines the formation of solid solutions Zn 1−x Cu x O or core-shell composite Zn 1−x Cu x O/Cu x O • The synthesis provides stabilization of Cu (I) and Cu (II) simultaneously. • 1–D Zn 1−x Cu x O (x = 0.025 and 0.05) showed improved performance photoactivity in As (III) oxidation on visible light • Presence of Cu(I) в Zn 1−x Cu x O/Cu x O intensify photoactivity through the formation of O 2 −