Hierarchical porous transition metal oxide nanosheets templated from waste bagasse: General synthesis and Li/Na storage performance

As a promising anode candidate, hierarchical porous transition metal oxide nanosheets (TMO-NSs) have attracted significant interest due to their various advantages of abundant active sites, high specific capacity and shortened ion/electrons transport pathways. Although the TMO-NSs have been developed in the past decades, the previous synthesis strategies have some drawbacks such as high cost, complex synthesis techniques, and the requirement of special instruments. Herein, we develop a generalized and facile biomorphic method to synthesize various controllable hierarchical porous TMO-NSs by using waste bagasse as biotemplate. Furthermore, the porosity and pore size of as-prepared hierarchical porous TMO-NSs can be adjusted by changing the precursor solution concentration. Novel hierarchical porous TMO-NSs have been successfully prepared for many ternary or binary TMO, such as NiFe₂O₄, ZnFe₂O₄, ZnMn₂O₄, NiO and ZnO. Owing to their unique nanostructure, as-synthesized hierarchical porous TMO-NSs show an excellent electrochemical performance when used as anode for Li/Na-ion batteries. We believe that various hierarchical porous TMO-NSs available from the green, economical and convenient biomorphic strategy may lead to further developments in research and application on TMO-NSs materials.