Role of reactive species in the photocatalytic degradation of amaranth by highly active N-doped WO$_3$

Bulletin of Materials Science

关键词: Nitrogen doping;    photocatalysis;    visible light active;    reactive species;    amaranth.;   

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

A novel, highly visible light active N-doped WO$_3$ (N-WO$_3$) is successfully synthesized via thermal decompositionof peroxotungstic acid–urea complex. The photocatalytic activity of N-WO$_3$ is evaluated for the degradation ofamaranth (AM) dye under visible and UVA light along with the role of reactive species, which has not yet been studiedfor N-WO$_3$ photocatalysts. Doping of N into substitutional and interstitial sites of WO$_3$ is confirmed by X-ray photoelectronspectroscopy and X-ray absorption near-edge spectroscopy. At a pH of 7, 1 g l$^{−1}$ of N-WO$_3$ can completely degrade10 mg l$^{−1}$ of AM within 1 h under visible and UVA light. For the degradation of AM by N-WO$_3$ under visible and UVAlight, h$^+$ is found to be the main reactive species, while ${}^{\bullet}$OH contributes to a lesser extent. On the contrary, ${}^{1}$O$^2$, ${}^{\bullet}$O$^{−}_2$ and e$^{−}$show negligible roles. The crucial role of h$^+$ indicates effective suppression of electron–hole recombination after N doping.Dye sensitization and oxidation by reactive species are found to be the major pathway for the degradation of AM undervisible and UVA light, respectively.

【 授权许可】

CC BY