UV-Vis-NIR diffuse reflectance spectra (a) and Tauc plots (b) of the calcined TiO2 samples

Sep 2, 2026

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UV-Vis-NIR diffuse reflectance spectra of calcined TiO2 samples are presented in Figure 1(a), denoted as DI-OEt/Pt, DI-OEt-UV/Pt, DI-OEt, P25, and ES-OEt. These spectra illustrate the absorbance (100 - R) as a function of wavelength from 300 to 800 nm. The Tauc plots, derived from the diffuse reflectance data, are shown in Figure 1(b), representing E*F(R) against energy in eV, with a fitted line to determine the band gap energy. The samples exhibit distinct spectral features, particularly in the UV region, indicating variations in their optical properties and electronic band structures. The DI-OEt/Pt sample shows relatively high absorbance across the entire measured range, while ES-OEt exhibits a sharper drop in absorbance at shorter wavelengths. The Tauc plots provide a method to estimate the optical band gap of the semiconductor materials. The bending point and the slope of the linearized Tauc plot are crucial for determining the band gap energy. The presence of Pt in DI-OEt/Pt and DI-OEt-UV/Pt suggests a modification, possibly for enhanced photocatalytic or catalytic activity, which is reflected in their spectral responses. The P25 sample, a common benchmark for TiO2 photocatalysis, serves as a reference. The ES-OEt sample, synthesized using a different precursor or method, shows different optical absorption characteristics. Further analysis of these spectra and Tauc plots is essential for correlating the material's structure and composition with its optoelectronic properties, which are critical for applications such as photocatalysis and solar energy conversion. The detailed analysis of the plot allows researchers to understand the electronic transitions and the energy required to excite electrons from the valence band to the conduction band.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages11

Reading Time28 min

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UV-Vis-NIR diffuse reflectance spectra (a)

Tauc plots (b)

FAQs

What does Figure 1(a) illustrate regarding the TiO2 samples?

Figure 1(a) displays the UV-Vis-NIR diffuse reflectance spectra of various calcined TiO2 samples, showing their absorbance (100 - R) across wavelengths from 300 to 800 nm.

What is the purpose of the Tauc plot in Figure 1(b)?

The Tauc plot in Figure 1(b) is used to estimate the optical band gap energy of the semiconductor materials by plotting E*F(R) against energy (eV).

What does the presence of Pt in some samples suggest?

The inclusion of Pt in samples like DI-OEt/Pt and DI-OEt-UV/Pt suggests a modification aimed at enhancing photocatalytic or catalytic performance, which is indicated by their different spectral responses compared to unmodified samples.

Sep 2, 2026

Uploaded by Đào