TiO2-ZrO2 nanocomposite with tetragonal zirconia phase and photocatalytic degradation of Alizarin Yellow GG azo dye under natural sunlight

Equimolar TiO2-ZrO2nanocomposite was prepared by sol–gel method with predominant tetragonal phase for zirconia and investigated for photodegradation of Alizarin Yellow GG dye under natural sunlight. Interfacial contacts enabling Zr-O-Ti bonding with preferred orientation of (101)TiO2//(101)ZrO2were seen at heterojunctions, and partial Zr4+substitution in TiO2lattice enhanced the acidity of TiO2. Increase in surface area, pore size and pore volume in nanocomposite contributed to its superior adsorption for dye solution. TiO2-ZrO2showed much higher photocatalytic activity of 68% than by parent TiO2. EIS spectra of TiO2-ZrO2showed low impedance than titania supporting the higher activity of the nanocomposite photocatalyst.