Mn3O4/N‐Doped Graphite Catalysts from Wastewater for the Degradation of Methylene Blue. Issue 54 (6th September 2018) - Fan, Mengmeng
Abstract: The accelerating research interest in graphene involving the use of Hummers method has generated non‐negligible amount of wastewater containing residual graphite as well as Mn 2+ . In this paper, we report the first example of using this wastewater as precursor to prepare Mn3 O4 /N‐doped graphite (NG) composites through a facile solvothermal process. The mass fraction of Mn3 O4 in the composites was manipulated by adding various amounts of extra Mn 2+ . The conversion of Mn 2+ to Mn3 O4 nanoparticles and the N atoms doping were achieved by adding hydrazine hydrate and ammonia into the system. The as‐obtained Mn3 O4 /NG composites were well characterized by SEM, TEM, EDS, Raman, XPS, TGA, XRD and N2 adsorption–desorption experiments and showed excellent catalytic performances as well as stability in the degradation of a model organic pollutant methylene blue (MB). Theoretical simulation was also carried out to illustrate the structural features of the Mn3 O4 /NG composite. This work presents a novel idea of designing functional materials from waste precursors. Abstract : From trash to treasure : For the first time, the graphite oxide and Mn 2+ in the wastewater produced by the Hummers reaction were reused as precursors for the production of a catalyst for the degradation of methylene blue (MB). The best catalyst exhibited a large specific surface area of 592 m 2 g −1, a fast catalytic kinetics, excellent stability and high degradation rate towards MB (99.9 %).