Fabrication of porous Cl-NbO nanostructures with large surface areas for photodegradation of organic contaminant: Morphology evolution, performance, and mechanism.

Fabricating semiconductor photocatalysts with abundant oxygen vacancies and porous structures contributes to charge separation and surface photocatalytic degradation reactions. In this work, porous Cl-NbO nanostructures were synthesized via a calcination method using NbCl as the niobium and chlorine sources to achieve efficient tetracycline degradation under visible-light irradiation. Porous NbO nanostructures were formed during the calcination process accompanied by the generation of oxygen vacancies. The obtained Cl-NbO samples demonstrated significantly enhanced photocatalytic performance compared to commercial NbO. The synthesized Cl-NbO-450 sample exhibited the highest photocatalytic performance, achieving a maximal rate constant of 0.03093 min, which markedly surpassed that of commercial NbO. The remarkable enhancement in tetracycline degradation of the Cl-NbO photocatalysts was mainly attributed to the generation of oxygen vacancies and porous structures with large surface areas. Finally, the photodegradation pathways of tetracycline facilitated by the Cl-NbO photocatalysts and a plausible photocatalytic mechanism of the Cl-NbO photocatalysts were also investigated in this work.