Enhancement of Visible Light-Responsive Photocatalytic Efficiency by Using a Laccaic Acid-Modified Titanium Dioxide Photocatalyst

Montri Aiempanakit,Sakchai Laksee,Kritapas Laohhasurayotin,Weerachai Sangchay,Nattawan Worawannotai,Cheewita Suwanchawalit,Jariyaporn Sangkaworn

doi:10.21577/0103-5053.20220006

Abstract

In this study, a laccaic acid-modified TiO2 photocatalyst (Lac-TiO2) was prepared via an impregnation method with 0.50, 1.00, 2.50, and 5.00 wt.% laccaic acid. The products’ physical properties were examined through X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), X-ray photoemission spectroscopy (XPS), UV-Vis diffused reflectance spectroscopy (DRS), Fourier-transform infrared spectroscopy (FTIR), nitrogen adsorption/desorption, and photoluminescence (PL) spectroscopy. A possible photocatalytic mechanism was also proposed. XRD patterns revealed the anatase phase of TiO2 and Lac-TiO2 samples. High-magnification FE-SEM images showed that the TiO2 and Lac-TiO2 samples exhibited spherical-like structures. XPS results complementarily confirmed the presence of Ti, O, and C as the main elements of the Lac-TiO2 samples. Interestingly, the DRS spectra of the Lac-TiO2 samples extended into the visible region. FTIR spectra presented the characteristic bands of TiO2 and hydroxyl groups on the TiO2 surface. Instead of hydroxyl groups, the characteristic bands of laccaic acid were observed on the surface of the Lac-TiO2 samples. The photocatalytic properties of the Lac-TiO2 samples were evaluated in terms of methyl orange degradation under visible light irradiation. The Lac-TiO2 samples showed higher photocatalytic performance than the TiO2 sample.

Highlights

Photocatalytic oxidation has been widely explored in terms of the removal of contaminants, including toxic organic pollutants.[1,2,3] In this process, various substances, including semiconductor photocatalysts, are used.[4]
After modification with different amounts of laccaic acid, no apparent change was observed in the X-ray powder diffraction (XRD) patterns
The XRD results suggested that the combination of TiO2 and laccaic acid did not modify the crystal structure and the size of TiO2

Summary

Introduction

Photocatalytic oxidation has been widely explored in terms of the removal of contaminants, including toxic organic pollutants.[1,2,3] In this process, various substances, including semiconductor photocatalysts, are used.[4]. Laccaic acid-modified TiO2 (Lac‐TiO2) was prepared via an impregnation method. The effects of the amount of laccaic acid loaded on the TiO2 surface on the microstructure, optical properties, and photocatalytic activity of Lac-TiO2 were investigated. The photocatalytic activity of the as-prepared Lac-TiO2 samples was tested and compared with a pure TiO2 sample using methyl orange (MO) as a model pollutant.

Results

Conclusion