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Visible-light activated titania perovskite photocatalysts: Characterisation and initial activity studies

2005; Elsevier BV; Volume: 6; Issue: 4 Linguagem: Inglês

10.1016/j.catcom.2005.01.006

1873-3905

Daphne Qiong Fei, Tedi Hudaya, Adesoji A. Adesina,

TiO2 Photocatalysis and Solar Cells

The effect of partial substitution of the titanium cation on the optophysical properties and photocatalytic oxidation activity of sol–gel synthesised CeCoxTi1 − xO3 + δ perovskite system has been examined. BET surface areas of the perovskite specimens were generally higher (80–130 m2 g−1) than standard Degussa P25 (50 m2 g−1) titania. Although the presence of Ce improved BET area, increased Co content and high calcination temperature was detrimental to nanocrystallinity. Based on UV–Vis diffuse reflectance measurements, perovskite catalysts have significantly lower band-gap energy (1.45–2.15 eV) than P25 (3.2 eV), however, the drop in band-gap energy levelled off at x > 0.1. Using oxidative photodegradation of aqueous Nile Blue solution for activity evaluation, the CeCo0.05Ti0.95O3.97 perovskite sample was the best in the series with a conversion of 91% in the 3-h run and also most suitable for solar photocatalysis since it can be activated by visible light (λ < 785 nm).