Ultrafast azo dye degradation by alkylammonium-intercalated layered MnO2 films

Abstract Layered manganese oxide films intercalated with trimethylstearylammonium ions are a new adsorbent that degrades the recalcitrant azo dye Congo Red. The films not only capture Congo Red but initiate oxidative cleavage of azo bonds within 3 min by simple immersion. Spectroscopy shows that interlayer anion release coupled with Mn(IV) to Mn(III) reduction cooperatively drives this ultrafast degradation. Unlike conventional photocatalysis or surface adsorption, interlayer redox chemistry furnishes a confined reaction field with intrinsic degradative activity.