The photocatalytic activity of isomorphously substituted transition metal (TM) ions into the vanadosilicate AM-6 framework, at TM/V ratios of 0.025-0.10, has been investigated. All 0.025TM-substituted AM-6 products showed enhanced photocatalytic activity under UV light irradiation which was attributed to the bandgap photoexcitation of these products. The photocatalytic activity decreased with increasing TM concentrations (TM > 0.025). Under visible light irradiation, only 0.025Cr-AM-6 showed enhanced photocatalytic activity (k = 4.6 × 10−3 min−1 ± 4.0 × 10−4 min−1). This was attributed to the electron excitation for the interfacial charge-transfer in the visible light region. 0.025Fe-AM-6 (k = 3.1 × 10−3 min−1 ± 4.0 × 10−4 min−1), 0.025Co-AM-6 (k = 3.4 × 10−3 min−1 ± 6.0 × 10−4 min−1), and unmodified AM-6 (k = 2.9 × 10−3 min−1 ± 7.0 × 10−4 min−1) were inactive towards the photodegradation of methylene blue under visible light irradiation (direct photolysis k = 2.8 × 10−3 min−1 ± 4.0 × 10−4 min−1). This was likely attributed to the ineffectiveness of the electron excitation for the interfacial charge-transfer, as suggested by the UV–vis spectroscopic analyses.
|Number of pages||9|
|Journal||Journal of Photochemistry and Photobiology A: Chemistry|
|State||Published - Feb 15 2018|
- Bandgap energy
- Methylene blue
- Transition metals