Designing of 3D MnO2-graphene catalyst on sponge for abatement temperature removal of formaldehyde

The Mn-based catalysts, with low cost and high activity, are believed to be the effective composites for eliminating in-door formaldehyde (HCHO), while the powdered form nanosized catalysts are hardly to apply for practical application. Herein, hetero-structure of nanosheets manganese oxide (MnO2) encapsulating N-doping graphene sphere (GS) were deposited in network-like sponge for constructing 3D catalyst. The prepared MnO2GS-Sponge composite catalyst exhibited excellent performance for removing HCHO at room temperature compared with GS and commercial MnO2. The MnO2-GS with larger specific surface area (209.1 m(2).g(-1)) was dispersed evenly in 3D network of sponge, which facilitated exposing more activate sites and achieving fast transport kinetics accelerating catalytic reaction for converting 97.1 % of 100 ppm of HCHO continuously to CO2 for 120 h. Moreover, rely on the chemisorption of amino groups on N-doping GS surface, HCHO could be enriched even at low concentrations and efficient elimination (from 1000 ppb to12 ppb, at 35. in 48 h). The average oxidation state and infrared spectra analysis suggested that abundant oxygen vacancies on MnO2-GSSponge could be identified as surface-active sites of converting HCHO into the intermediates of dioxymethylene and formate. This work might inspire the designing 3D composite material for potential application in other fields of environmental engineering or energy industrial.

Automated summary

In this study, a 3D composite catalyst was designed, which used nanosheets manganese oxide (MnO2) encapsulating N-doping graphene sphere (GS), to effectively remove indoor formaldehyde. The catalyst had a larger specific surface area and uniform dispersion, which facilitated exposing more active sites and achieving fast transport kinetics for efficient catalytic reaction, converting formaldehyde into harmless substances. Moreover, through chemical adsorption, formaldehyde could be enriched and rapidly degraded even at low concentrations. This study provides inspiration for the potential application of 3D composite materials in fields such as environmental engineering and energy industry.