Boosting charge migration in V2O5 nanorods by niobium doping for enhanced photocatalytic activity. (31st August 2022)

• Record Type: Journal Article
• Authors: Basu, Soumya Shankar; Donode, Shweta Kishor; Sengupta, Sonali; Basu, Jayanta Kumar
• Is Part Of: New journal of chemistry. Volume 46:Number 36(2022)
• Page Start: 17527
• Page End: 17539
• Publication Date: 2022-08-31
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/d2nj02428d
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : Niobium dopants have improved the structural and optoelectronic properties of V2 O5 nanorods, resulting in enhanced charge kinetics for photocatalytic and photoelectrochemical activity. Abstract : This work aims to enhance the functionality of V2 O5 nanorods by niobium ion doping and discusses its effects on the photocatalytic activity of V2 O5 . As reflected in various structural and optoelectronic analyses, the dopant ions had a profound influence on the hydrothermally developed samples, which resulted in tailored nanorod architectures, improved crystallinity, and higher charge generation and separation. The similar dimensions and oxidation states of niobium and vanadium atoms have led to smooth substitutional doping among the layers of VO5 square pyramids constituting the orthorhombic V2 O5 unit crystals. This has led to the hybridization of V 3d and Nb 4d orbitals, which markedly improved their electronic conductivity. The boosted charge kinetics resulted in an optimum band gap of 2.0 eV and the least electron hole recombination in the 2 mol% Nb-doped samples. Accordingly, the 2 mol% Nb-doped samples achieved maximum photocatalytic degradation of complex organic caffeine, removing 91% in 2 hours. The 2 mol% Nb-doped samples also achieved maximum photocurrent generation in a photoelectrochemical cell. However, doping beyond 2 mol% deteriorated the catalytic activity due to the formation of mixed crystalline phases with excess Nb 5+ ions acting as electron hole recombination centres, resulting in poor charge transfer kinetics. The experimental results have been verified by DFT calculations on pure and doped unit cell geometries, which further revealed the synergistic influence of V 3d and Nb 4d orbitals in modifying the band gap of Nb-doped V2 O5 . Thus this work presents a rational design and thorough investigation of Nb-doped V2 O5 nanorods for enhanced photocatalytic activity.