Nb2O5 supported in mixed oxides catalyzed mineralization process of methylene blue

Abstract

Heterogeneous photocatalysis has become a significant green technology for water treatment. The application of Nb 2 O 5 catalyst for the photodegradation of contaminants has merged as an important tool to this process. Furthermore, it is known that catalytic phases supported on metal oxides are an alternative method for enhancing its activity. In this work, supported Nb 2 O 5 on mixed oxides as catalyst was applied to degrade methylene blue dye, leading to almost 100% of dye degradation without the need of any additives, after only three hours of sunlight exposure. The effect of catalyst concentration, exposure time and light source were investigated. The best catalyst activity was found at 1.5 g L À1 and for higher catalyst concentrations the degradation was kept constant. Plausible intermediates of this degradation process were observed and characterized by NMR, LC/MS and CZE techniques. After degradation, the catalyst was recovered and could be further re-applied in other three reaction cycles without significant loss of catalytic activity.

Photoactivity of nanostructured porous Nb2O5: Effect of Pt, Ta, Cu, and Ti impregnation

“…In addition, oxygen vacancies are created when Nb 2 O 5 is impregnated with tantalum, which contributes to bandgap narrowing and consequently to increased absorbance in visible light 53 . For Carvalho et al., 54 the increases of photon absorption, which generate more electron–hole pairs, contribute to increases of photodegradation activity.…”

Raman Spectroscopy for Characterization of Hydrotalcite-like Materials Used in Catalytic Reactions

“…De Carvalho et al [65] carried out the application of a niobium oxide catalyst supported on mixed oxide derived from LDH in the photodegradation of the methylene blue dye. The synthesis of ZnAl-LDH was performed by co-precipitation.…”

Facile Synthesis of Uniform Mesoporous Nb2O5 Micro-Flowers for Enhancing Photodegradation of Methyl Orange

“…Among the semiconductor-based photocatalysts, Niobium materials are promising materials as photocatalysts and solid acid catalysts, thus has been widely applied in different kinds of fields [11][12][13]. Because of the excellent properties like non-toxicity, corrosion resistance, high stability, and lots of surface acid sites, Niobium oxide (Nb 2 O 5 ) has a wide range of catalytic activities for various reactions including dehydration, hydration, dehydrogenation, and many types of oxidation reactions [11,[14][15][16][17][18].…”