Synthesis of highly crystalline photocatalysts based on TiO2 and ZnO for the degradation of organic impurities under visible-light irradiation

Abstract

A TiO 2 -ZnO binary oxide system (with molar ratio TiO 2 :ZnO = 8:2) was synthesized by a hydrothermal method, assisted by calcination at temperatures of 500, 600 and 700 °C, using zinc citrate as the precursor of ZnO. The morphology (SEM, TEM), crystalline structure (XRD, Raman spectroscopy), diffuse reflectance spectra (DRS), chemical surface composition (EDXRF), porous structure parameters (low-temperature N 2 sorption) and characteristic functional groups (FT-IR) of the TiO 2 -ZnO oxide materials were comprehensively analyzed. The novelty of this work is the observation of the coexistence of the crystalline structures of anatase and ZnTiO 3 in TiO 2 -ZnO oxide materials. Moreover, it is shown that the obtained materials absorb visible radiation. The key stage of the study was the evaluation of the photocatalytic activity of the TiO 2 -ZnO binary oxide systems in the degradation of model organic pollutants: C.I. Basic Red 1, C.I. Basic Violet 10, C.I. Basic Blue 3 and 4-nitrophenol. For all synthesized materials, a high efficiency of degradation of the model organic impurities was demonstrated. The results show that the synthesized products may be materials of interest for use in the degradation of organic pollutants. Moreover, the kinetics of the photocatalytic degradation of selected organic compounds were determined based on the Langmuir-Hinshelwood equation, assuming a pseudo-first-order (PFO) reaction.

Photocatalytic Methylene Blue Degradation of Electrospun Ti–Zn Complex Oxide Nanofibers

“…Nanostructured ZnO has frequently been fabricated, and it has been used in composites with TiO 2 for photocatalysts. Many ZnO–TiO 2 composite structures have been reported [ 6 , 18 , 19 , 33 , 34 , 35 , 36 ].…”

Optimization of the Technological Parameters for Obtaining Zn-Ti Based Composites to Increase the Performance of H2S Removal from Syngas

“…Similar trend was recorded for pore volume of synthetized composites namely, 0.031 cm 3 /g for ZT-500, 0.015 cm 3 /g for ZT-600, and 0.014 cm 3 /g for ZT-700. This very small pore volume suggests a non-porous-like structure of the synthetized composites [27,28].…”

Effects of Electrospinning Parameters on the Microstructure of PVP/TiO2 Nanofibers

“…Titanium dioxide has excellent chemical, electrical, and optical properties, as well as chemical stability. For that reason, it is widely used in many fields of study and industry, such as photocatalysts, organic solar cells, sensors, dental implants, and other applications [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. It is a very useful material and is commonly used for photocatalysts due to its photoactivity, high stability, low cost, and safety for the environment and humans [ 7 , 15 , 16 ].…”