Controlled Chemical Transformation and Crystallization Design for the Formation of Multifunctional Cu-Doped ZnO/ZnAl2O4 Composites

Photoactive Cu-doped ZnO–ZnAl 2 O 4 ceramic nanocomposites and coatings were prepared by polymer-salt method. The luminescent spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction methods were used for the study the structure, morphology and materials properties. The nanocomposites consist of small hexagonal ZnO and cubic ZnAl 2 O 4 nanocrystals having size about 10 nm. The study of luminescence properties shows that prepared nanocomposites can be used as light down-converters that transfer short-wave ultraviolet (UV-C) radiation into long-wave ultraviolet (UV-A) and visible spectral range. These nanocomposites can be very attractive in photovoltaic applications as spectral down-converters. Also obtained nanocomposites demonstrate the ability to generate chemically active singlet oxygen under UV-A radiation and blue light. The experiments show that Cu-doped ZnO–ZnAl 2 O 4 materials demonstrate antibacterial activity against gram-positive bacteria. Graphical Abstract