Ultralong α-MnO2 Nanowires Capable of Catalytically Degrading Methylene Blue at Low Temperature

Abstract

Ultralong MnO2 nanowires, which can effectively catalyze H2O2 to generate radicals for degrading methylene blue (MB) at low temperature (5.0 °C), are prepared by hydrothermal method. The MnO2 nanowires catalytically degrade 98.1% of MB within 30 min and degradation efficiency is about 93.0% after 5 cycles at 5.0 °C. The yield of ·OH and ·O2− radicals within 30 min is 39.33 $${\text{mg}}\;{{\text{g}}_{{\text{Mn}}{{\text{O}}_2}}}^{{ - 1}}$$ and 1.29 $${\text{mg}}\;{{\text{g}}_{{\text{Mn}}{{\text{O}}_2}}}^{{ - 1}}$$ , respectively. Excellent catalytic degradation performances for MB at 5.0 °C including catalytic efficiency, reusability and yield of radicals concerning synthesized ultralong MnO2 nanowires are revealed.