A Versatile Nb₂O₅/SnO₂ Heterostructure for Different Environmental Purposes: Water Treatment and Artificial Photosynthesis

Graphical Abstract

Heterogeneous photocatalysis: The Nb₂O₅/SnO₂ heterostructure, prepared by means of a facile hydrothermal method, showed higher photocatalytic performance for contaminant degradation, rhodamine B dye and amiloride medicine, and CO₂ photoreduction, producing syngas. Besides, cationic species adsorption was higher over the heterostructure than isolated Nb₂O₅, showing the versatility of the as prepared heterostructured composite.

Abstract

A versatile Nb₂O₅/SnO₂ heterostructure, adequate for different processes, was successfully synthesized by adding SnO₂ to the hydrothermal Nb₂O₅ synthesis process. The presence of SnO₂ dispersed over Nb₂O₅ did not modify its crystalline structure. On the other hand, the properties of the material were strongly affected by coupling the semiconductors. The heterostructure exhibited enhanced photocatalytic performance compared to pure Nb₂O₅ in the degradation of rhodamine B dye and the amiloride medication under UV radiation, as well as during CO₂ photoreduction. Moreover, the heterostructured material was more efficient at removing the cationic species methylene blue dye and Mn (II) from the aqueous solution through adsorption than pure Nb₂O₅. Its versatility has been explained by reference to the negative surface charge induced by SnO₂ and the charge separation in the heterostructure, which increases their lifetimes, making it possible to reach the surface of the material and promote the reaction in the oxidative and reductive processes. Our results indicate that coupled Nb₂O₅/SnO₂ can be a unique platform to different forms of environmental treatment.