Rapid formation of AgnX(X = S, Cl, PO4, C2O4) nanotubes via an acid-etching anion exchange reaction

Abstract

This work presents a rapid nanotube fabrication method for a series of silver compounds Ag_nX, such as Ag₂S, AgCl, Ag₃PO₄, and Ag₂C₂O₄, from pregrown Ag₂CO₃ nanorod templates. The anion exchange process involved takes place in non-aqueous solutions just at room temperature and completes within 10 minutes. An acid-etching anion exchange reaction mechanism has been proved underneath the transformation process from Ag₂CO₃ nanorods to Ag_nX nanotubes by the observation of an intermediate yolk–shell nanostructure. It has been found that the final structure of the products can be conveniently controlled by simply varying the concentration of H_nX acids, and the organic solvents employed play a vital role in the formation of the nanotubes by effectively controlling the diffusion rates of different species of reacting ions. As a demonstration, the as-prepared AgCl and Ag₃PO₄ nanotubes exhibit enhanced photocatalytic activity and favorable recyclability for the photodegradation of rhodamine B (RhB) under visible-light irradiation.