Note: Rapid reduction of graphene oxide paper by glow discharge plasma.

This note reports on a novel method for the rapid reduction of graphene oxide (GO) paper using a glow discharge plasma reactor. Glow discharge is produced and sustained between two parallel-plate graphite electrodes at a pressure of 240 mTorr. By exposing GO paper at the junction of negative-glow and Faraday-dark area for 4 min, the oxygen-containing groups can be effectively removed (C/O ratio increases from 2.6 to 7.9), while the material integrality and flexibility are kept well. Electrochemical measurements demonstrate that the as-obtained reduced GO paper can be potentially used for supercapacitor application.

Pyrolysis mechanism study of minimally damaged hemicellulose polymers isolated from agricultural waste straw samples.

The pyrolysis mechanism of hemicellulose has been investigated using two minimally damaged hemicellulose polymers isolated from two agricultural straw samples. The obtained hemicelluloses have been characterized by multiple methods, and the results showed that they were mainly composed of l-arabino-4-O-methyl-d-glucurono-d-xylan. Their O-acetyl groups and high degrees of polymerization and branching were well preserved. Their pyrolyses were subsequently investigated by TG-FTIR and Py-GC/MS. The evolutions of four typical volatile components and the distributions of eight product species were scrutinized. A DG-DAEM kinetic model was applied to quantify the contributions of two major pyrolytic routes for devolatilization during hemicellulose pyrolysis. A mean activation energy of 150kJ/mol for the formation of volatiles was derived. The thermal stability of each bond in four typical fragments of hemicellulose was assessed by DFT study, and the deduced decomposition pathways were in agreement with experimental analysis.

A novel method of microwave heating mixed liquid-assisted regeneration of V2O5-WO3/TiO2 commercial SCR catalysts.

An experimental study on the regeneration of deactivated SCR catalysts was carried out using a microwave-assisted method containing three steps of washing with mixed liquid of ethanol and water, impregnating, and drying. After the regeneration treatment, NO conversion at 320 °C increased from 39 to 90% and vanadium content increased by 62.2%, which were much higher than those regenerated by the traditional method. The more impregnated vanadium was due to the fact that the rapid evaporation of mixed liquid inside the catalyst channels led to the enlargement of surface areas by creating more pores on the catalysts. Meanwhile, with the increasing concentrations of ethanol, the heating rate of the mixed liquid increased, and the volume after complete evaporation of the mixed liquid was gradually reduced. Since higher heating rate and lager volume after the liquid evaporation could help to create more pores, therefore, when the volume ratio of ethanol/mixed solution was 20%, the catalyst obtained the maximum specific surface area, which significantly increased to ca. 123% compared with the deactivated catalyst. In addition, the catalyst dried by microwave exhibited better catalytic activity than that dried in conventional oven. Therefore, this method showed great potential in industrial applications.