Facile In-Situ Synthesis of Manganese Dioxide Nanosheets on Cellulose Fibers and their Application in Oxidative Decomposition of Formaldehyde

In situ synthesis of manganese dioxide was carried out under ambient conditions on porous cellulose fibers as support. MnO 2 /cellulose composites with different MnO 2 loadings were obtained by tuning the concentration of aqueous KMnO 4 . Physical and chemical properties of the MnO 2 /cellulose composites were characterized by SEM, TEM, and XRD. When the concentration of aqueous KMnO 4 falls in the range of 6.33–12.6 mM, the obtained MnO 2 shows a nanosheet morphology and is uniformly coated on the cellulose fiber. The catalytic activities of MnO 2 /cellulose composites were investigated for the oxidative decomposition of HCHO. The nanostructured MnO 2 /cellulose composites show excellent catalytic performance for the oxidative decomposition of HCHO. Among them, 8.86 wt % MnO 2 /cellulose has the highest catalytic activity. The HCHO conversion per milligram of MnO 2 of 8.86 wt % MnO 2 /cellulose is about 9–17 times as high as that of birnessite MnO 2 powder prepared by a hydrothermal method. The catalytic activity was found to be dependent not only on the content of MnO 2, but also on the adsorption of HCHO on cellulose fibers as well. These two factors are supposed to give rise to the highest catalytic activity for 8.86 wt % MnO 2 /cellulose. The high efficiency combined with the easy applicability makes the MnO 2 /cellulose composites more promising for practical applications as compared to MnO 2 powders.