Hydrothermal carbon（HC） was prepared from walnut shells, which are abundant in Northeastern China. The prepared HC was used as a precursor to produce mtric acid modified carbon（MC）. The hydrothermal carbonization ...Hydrothermal carbon（HC） was prepared from walnut shells, which are abundant in Northeastern China. The prepared HC was used as a precursor to produce mtric acid modified carbon（MC）. The hydrothermal carbonization included dehydration and decarboxylation processes wherein the hemicellulose was completely decomposed and the celhilose was partly decomposed, with some oxygen-containing functional groups being produced. The aromati- city, specific surface area and pore content of the HC increased, but its polarity decreased. With 6 mol/L nitric acid and a modification time of 15 min, the specific surface area and pore content decreased, but the proportion of oxy- gen-containing fimctional groups on the surface increased significantly, thereby improving the dye adsorption performance. The adsorption of methylene blue and malachite green was best desclibed by the pseudo-second-order kinetic and Langmuir isotherm models. The adsorption capacity of MC was determined to be much larger than that of HC.展开更多
文摘Hydrothermal carbon（HC） was prepared from walnut shells, which are abundant in Northeastern China. The prepared HC was used as a precursor to produce mtric acid modified carbon（MC）. The hydrothermal carbonization included dehydration and decarboxylation processes wherein the hemicellulose was completely decomposed and the celhilose was partly decomposed, with some oxygen-containing functional groups being produced. The aromati- city, specific surface area and pore content of the HC increased, but its polarity decreased. With 6 mol/L nitric acid and a modification time of 15 min, the specific surface area and pore content decreased, but the proportion of oxy- gen-containing fimctional groups on the surface increased significantly, thereby improving the dye adsorption performance. The adsorption of methylene blue and malachite green was best desclibed by the pseudo-second-order kinetic and Langmuir isotherm models. The adsorption capacity of MC was determined to be much larger than that of HC.
