Search

Removing CO2gas to address the global climate crisis is one of the most urgent agendas. To improve the CO2adsorption ability of activated carbon, nitrogen plasma surface treatment was conducted. The effect of nitrogen plasma treatment on the surface chemistry and pore geometry of activated carbon was extensively analyzed. The porosity and surface groups of the activated carbon varied with the plasma treatment time. By plasma treatment for a few minutes, the microporosity and surface functionality could be simultaneously controlled. The changed microporosity and nitrogen groups affected the CO2adsorption capacity and CO2adsorption selectivity over N2. This simultaneous surface etching and functionalization effect could be achieved with a short operating time and low energy consumption.

In this study, we investigate the opportunity of using waste tire char as a cathode material for lithium-ion primary batteries (LPBs). The char obtained by carbonizing waste tires was washed with acid and thermally fluorinated to produce CFX. The structural and chemical properties of the char and CFXwere analyzed to evaluate the effect of thermal fluorination. The carbon structure of the char was increasingly converted to CFXstructure as the fluorination temperature increased. In addition, the manufactured CFX-based LPBs were evaluated through electrochemical analysis. The discharge capacity of the CFXreached a maximum of 800 mAh/g, which is comparable to that of CFX-based LPBs manufactured from other carbon sources. On the basis of these results, the use of waste tire char-based CFXas a cathode material for LPBs is presented as a new opportunity in the field of waste tire recycling.

To investigate the effect of the catalyst and metal–support interaction on the methane decomposition behavior and physical properties of the produced carbon, catalytic decomposition of methane (CDM) was studied using Ni/SiO2catalysts with different metal–support interactions (synthesized based on the presence or absence of urea). During catalyst synthesis, the addition of urea led to uniform and stable precipitation of the Ni metal precursor on the SiO2support to produce Ni-phyllosilicates that enhanced the metal–support interaction. The resulting catalyst upon reduction showed the formation of uniform Ni0particles (< 10 nm) that were smaller than those of a catalyst prepared using a conventional impregnation method (~ 80 nm). The growth mechanisms of methane-decomposition-derived carbon nanotubes was base growth or tip growth according to the metal–support interaction of the catalysts synthesized with and without urea, respectively. As a result, the catalyst with Ni-phyllosilicates resulting from the addition of urea induced highly dispersed and strongly interacting Ni0active sites and produced carbon nanotubes with a small and uniform diameter via the base-growth mechanism. Considering the results, such a Ni-phyllosilicate-based catalyst are expected to be suitable for industrial base grown carbon nanotube production and application since as-synthesized carbon nanotubes can be easily harvested and the catalyst can be regenerated without being consumed during carbon nanotube extraction process.