Effect of the Titanium Isopropoxide:Acetylacetone Molar Ratio on the Photocatalytic Activity of TiO2 Thin Films.

Jekaterina Spiridonova,Atanas Katerski,Marina Krichevskaya,Ilona Oja Acik,Mati Danilson,Malle Krunks

doi:10.3390/molecules24234326

Jekaterina Spiridonova, Atanas Katerski + Show 4 more

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https://doi.org/10.3390/molecules24234326

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Abstract

TiO2 thin films with different titanium isopropoxide (TTIP):acetylacetone (AcacH) molar ratios in solution were prepared by the chemical spray pyrolysis method. The TTIP:AcacH molar ratio in spray solution varied from 1:3 to 1:20. TiO2 films were deposited onto the glass substrates at 350 °C and heat-treated at 500 °C. The morphology, structure, surface chemical composition, and photocatalytic activity of the obtained TiO2 films were investigated. TiO2 films showed a transparency of ca 80% in the visible spectral region and a band gap of ca 3.4 eV irrespective of the TTIP:AcacH molar ratio in the spray solution. TiO2 films consist of the anatase crystalline phase with a mean crystallite size in the range of 30–40 nm. Self-cleaning properties of the films were estimated using the stearic acid (SA) test. A thin layer of 8.8-mM SA solution was spin-coated onto the TiO2 film. The degradation rate of SA as a function of irradiation time was monitored by Fourier-transform infrared spectroscopy (FTIR). An increase in the TTIP:AcacH molar ratio from 1:4 to 1:8 resulted in a ten-fold increase in the photodegradation reaction rate constant (from 0.02 to the 0.2 min−1) under ultraviolet light and in a four-fold increase under visible light.

Highlights

The synthesis and optimization of TiO2 thin films is a rapidly developing topic in the field of environmental engineering due to their great potential in pollution treatment and self-cleaning properties
The results resultsof of this study demonstrate that an increase in the amount of theacetylacetone unchelated thin films, since all the obtained films were annealed at the same temperature
TiO2 thin films were deposited onto borosilicate glass substrates by the ultrasonic spray pyrolysis technique

Summary

Introduction

The synthesis and optimization of TiO2 thin films is a rapidly developing topic in the field of environmental engineering due to their great potential in pollution treatment and self-cleaning properties. It is widely used in our homes (in windows, doors, and shower enclosures), in automobile windshields, in electronic device screens, and in construction materials for modern skyscrapers. Keeping the surface of the glass clean is not an easy task; due to its optical transparency, all the dirt particles, stains, and fingerprints which present on the surface are noticeable [1]. More and more skyscrapers are built worldwide because they give us an opportunity to design a good deal of real estate using a relatively small ground area.

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