Effect of Zn Dopant on Crystal Structure, Optical Properties, and Photocatalytic Activity of TiO2/ZnxNi1-xFe2O4 Composites by Co-Precipitation Method for Degrading Liquid Waste of the Textile Industry Arisma Nurul Fauziyah, Khorifathul Khoiriyah, Vindy Yurike Oktavia, Herlin Pujiarti, and Joko Utomo*
Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang
Jl. Semarang 5 Malang 65145, Indonesia
*joko.utomo.fmipa[at]um.ac.id
Abstract
TiO2/ZnxNi1-xFe2O4 nanocomposites (x = 0- 0.2- 0.4- 0.6- 0.8- and 1) were synthesized using co-precipitation method at annealing temperature of 600oC for 3 hours. X-ray diffraction pattern showed high percentage of anatase TiO2 phase and slight proportion of Zn-NiFe2O4 spinel ferrite phase. The lattice parameters in all samples are in the range a = b = 3.782-3.791 A and c = 9.487-9.524 A. Crystal size tends to decrease with increasing Zn content between 11.34-15.64 nm. The results of SEM characterization showed that the particle size of the sample x = 0.2 and 0.8 were 95.9 nm and 110.8 nm, respectively. The FTIR spectra measured at a wave number of 400-4000 cm-1. Vibration of metal ion with oxygen (M-O) occurred at wave number of 416.62 cm-1, which confirmed might be the spinel ferrite in the TiO2/ZnxNi1-xFe2O4 nanocomposites. The presence of the titanium dioxide phase was confirmed by wave number 671.64 cm-1 in the FTIR spectrum which is the Ti-O-Ti vibration. The energy gap of TiO2/ZnxNi1-xFe2O4 nanocomposites decreased with the addition of Zn content in the range of 2.77-3.01 eV. The value obtained is lower than the band gap energy of pure TiO2. The highest degradation of RhB dye was 35.94% with a degradation rate of 0.002 minutes-1 on sample x = 0.2 for 120 minutes with 10 watt UV irradiation.
