In situ synthesis of MnO2 coated cellulose nanofibers hybrid for effective removal of methylene blue

• A one-step synthetic method was developed to construct MnO2/CNFs hybrid.
• CNFs acted as both reducing agent and ultralights support for MnO2 nanosheets.
• The hybrid exhibited extraordinary decolorization efficiency.
• Both the oxidation and adsorption of MB were discussed.

A one-step and energy-efficient synthetic method was developed to fabricate manganese dioxide (MnO2)/cellulose nanofibers (CNFs) hybrid. In this process, bamboo CNFs acted as both a reducing reagent for the Mn (VII) and an ultralight support for the generated MnO2 nanosheets. Neither additional reducing reagents nor heating were adopted during the synthesis process. The phase constitutions, crystal structure and morphology of the hybrid were systematically investigated. Both oxidative and adsorptive decolorization of methylene blue (MB) were investigated to evaluate its efficiency on dye wastewater treatment. The results showed that the few-layer MnO2 nanosheets deposited on CNFs exhibited high decolorization efficiency for the oxidation and adsorption of MB. When slurry containing 25 mg MnO2/CNFs hybrid was dispersed in 25 mL 80 mg L−1 MB solution, the removal of MB was more than 99.8% within 2 min.