Journal of Sol-Gel Science and Technology

, Volume 61, Issue 1, pp 1–7

Band-gap energy estimation from diffuse reflectance measurements on sol–gel and commercial TiO2: a comparative study

Original Paper

DOI: 10.1007/s10971-011-2582-9

Cite this article as:
López, R. & Gómez, R. J Sol-Gel Sci Technol (2012) 61: 1. doi:10.1007/s10971-011-2582-9


A comparison of the band gap energy estimated from UV–vis reflectance spectra of TiO2 powders prepared by sol–gel route versus commercial TiO2 powders, nanopowder, bulkpowder and P25 is reported. The experimental results obtained from the optical absorption spectra were reported for all the TiO2 samples. Graphic representations were used to calculate Eg: absorbance versus λ; F(R) versus E; (F(R) )n versus E, with n = ½ for an indirect allowed transition and n = 2 for a direct allowed transition. From the results, it could be seen that Eg strongly varied according to the equation used for the graphic representation. Differences in Eg up to 0.5 eV for the same semiconductor depending on the transition chosen were observed. Accurate Eg estimation in the four semiconductors studied was obtained by using the general equation α () ≈ B ( − Eg)n (where α ~ F(R)) and indirect allowed transition.


Titanium dioxide semiconductorBand gap calculationTitanium dioxide electronic transitionsKubelka–Munk method

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  1. 1.Grupo ECOCATAL, Área de Catálisis, Departamento de QuímicaUniversidad Autónoma Metropolitana-IztapalapaMexicoMexico