Facile and template-free preparation of α-MnO2 nanostructures and their enhanced adsorbability

In this paper, nanostructured MnO2 materials were successfully prepared through a simple and template-free hydrothermal method. X-ray diffraction pattern indicates that the as-prepared nanomaterials are α-MnO2. Transmission Electron Microscopy and Scanning Electron Microscopy images demonstrate that nanostructured rod-clusters α-MnO2 could be evolved from the nanorods. Brunauer–Emmett–Teller (BET) surface area measurement was employed to characterize the surface property. Moreover, the as-obtained (α-MnO2) nanomaterials could act as an efficient adsorbent to remove Congo Red and Methlylene Blue. More significantly, the nanomaterials are nontoxic and environmentally friendly via biological methylthiazolyldiphenyltetrazoliumbromide assay experiments. Its nontoxic and enhanced adsorbability properties guarantee their safe applications in environmental protection and industrial aspects.

Graphical abstract. The as-obtained (α-MnO2) nanomaterials could act as an adsorbent to remove Conge red. More significantly, the nanomaterials are nontoxic and environmentally friendly though a biological MTT assay experiment.Plots of the capacity to remove Conge red with time by the commercial and new-prepared α-MnO2. Inset shows absorption of Congo Red with time by new-prepared rod-clusters α-MnO2 (0, 10, 20, 40 and 60 min, respectively).Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Nanostructured α-MnO2 was prepared through a template-free hydrothermal method. ► The obtained α-MnO2 could act as effective adsorbents to remove organic dyes. ► The obtained adsorbents are environmentally friendly.