Branched Mesoporous Mn₃O₄ Nanorods: Facile Synthesis and Catalysis in the Degradation of Methylene Blue

Abstract

Branched MnOOH nanorods with diameters in the range of 50-150 nm and lengths of up to tens of micrometers were prepared by using potassium permanganate (KMnO(4)) and PEG 400 (PEG=polyethylene glycol) as starting materials through a simple hydrothermal process at 160 °C. After annealing at 300 °C under a N(2) atmosphere for 5 h, MnOOH nanorods became gradually dehydrated and transformed into mesoporous Mn(3)O(4) nanorods with a slight size-shrinking. The as-obtained mesoporous Mn(3)O(4) nanorods had an average surface area of 32.88 m(2) g(-1) and a mean pore size of 3.7 nm. Through tuning the experimental parameters, such as the annealing atmosphere and temperature, β-MnO(2), Mn(2)O(3), Mn(3)O(4), MnO, and Mn(5)O(8) were selectively produced. Among these structures, mesoporous Mn(3)O(4) nanorods were efficient for the catalytic degradation of methylene blue (MB) in the presence of H(2)O(2) at 80 °C.

Novel magnetic porous carbon spheres derived from chelating resin as a heterogeneous Fenton catalyst for the removal of methylene blue from aqueous solution

“…7b). Two characteristic peaks (614 and 664 nm) are observed from the starting solution of MB, similar to those reported previously [53,54]. Following addition of MCS-1100, H 2 O 2 and NH 2 OH, the MB absorption peak intensities were observed to decrease with time.…”

Hydrothermal synthesis of γ-MnOOH nanorods and their conversion to MnO2, Mn2O3, and Mn3O4 nanorods

“…It is well-known that metal hydroxides can convert to the corresponding metal oxides by dehydration under thermal annealing [48,49]. The annealing parameters (i.e., atmosphere, time and temperature) are fundamental to control the oxidation states and morphologies of the final products.…”

Glucose-based carbon coated MnO hierarchical architectures with enhanced photostability and photocatalytic activity

“…The morphology of MnO x can be controlled to 48 exhibit different hierarchical structures, which may provide novel materials for potential 49 applications as oxidation materials, catalytic materials, electrode materials [1][2][3][4][5][6][7][8]. Amorphous carbon was widely used as unique coating for nanostructured materials 64 such as metal oxides, ceramics.…”