This study developed a method to fabricate a surface-oxidized rigid carbon foam(ORCF)with hierarchical macro-nanoporous structure via KOH activation of the carbon foam with two kinds of macropores followed by HNO_(3) ...This study developed a method to fabricate a surface-oxidized rigid carbon foam(ORCF)with hierarchical macro-nanoporous structure via KOH activation of the carbon foam with two kinds of macropores followed by HNO_(3) hydrothermal oxidation.The structures of the prepared ORCF were characterized using scanning electron microscopy,transmission electron microscopy,X-ray diffraction,Fourier transform infrared(FTIR)spectra,X-ray photoelectron spectroscopy,and N_(2) adsorption-desorption analyzer.Results demonstrate that the ORCF possesses a fluffy and porous structure with rich oxygen-containing groups.There are numerous through-holes on its pore surfaces connected with two-level macropores forming hierarchical macroporous channels.Meanwhile,the ORCF remains a good bulk structure with a compression strength of 0.74 MPa at a bulk density of 0.09 g cm^(−3).Batch adsorption experiments for malachite green(MG)and Pb^(2+) were studied through the single variable method to investigate the effects of different initial conditions on its adsorption process.The ORCF has maximum adsorption capacities for MG and Pb^(2+) of 587.68 mg g^(−1) and 157.80 mg g^(−1) with high partition coefficients of 17.41 mg g^(−1)μM^(−1) and 14.86 mg g^(−1)μM^(−1),respectively.The experimental data are suitable for Langmuir isotherm and Pseudo-secondorder kinetic models,which correspond to monolayer chemisorption.Thermodynamic analysis indicates that the adsorption process is spontaneous and endothermic.Moreover,the removal percentages of MG and Pb^(2+)by the ORCF could remain above 90%after five cycles,implying that the ORCF is an efficient adsorbent with good adsorption ability and cycling stability.展开更多
The stability of the photoluminescence (PS) has evidently improvedby HNO3 chemical oxidation The PL intensity and peak wavelength of PS were changed with theHNO3 of HNO3 concentration and oxidation time. Being diff...The stability of the photoluminescence (PS) has evidently improvedby HNO3 chemical oxidation The PL intensity and peak wavelength of PS were changed with theHNO3 of HNO3 concentration and oxidation time. Being different from other oxidation time. Being different from other oxidized ways, the PSoxidized by HNO3 remains remains sensitive to adsorbates. FTTR spectroscopic data suggest that these phenomena are attributed to the presence of HSi(SiaO30a)(a≤3)layer on PS surface.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51872049)。
文摘This study developed a method to fabricate a surface-oxidized rigid carbon foam(ORCF)with hierarchical macro-nanoporous structure via KOH activation of the carbon foam with two kinds of macropores followed by HNO_(3) hydrothermal oxidation.The structures of the prepared ORCF were characterized using scanning electron microscopy,transmission electron microscopy,X-ray diffraction,Fourier transform infrared(FTIR)spectra,X-ray photoelectron spectroscopy,and N_(2) adsorption-desorption analyzer.Results demonstrate that the ORCF possesses a fluffy and porous structure with rich oxygen-containing groups.There are numerous through-holes on its pore surfaces connected with two-level macropores forming hierarchical macroporous channels.Meanwhile,the ORCF remains a good bulk structure with a compression strength of 0.74 MPa at a bulk density of 0.09 g cm^(−3).Batch adsorption experiments for malachite green(MG)and Pb^(2+) were studied through the single variable method to investigate the effects of different initial conditions on its adsorption process.The ORCF has maximum adsorption capacities for MG and Pb^(2+) of 587.68 mg g^(−1) and 157.80 mg g^(−1) with high partition coefficients of 17.41 mg g^(−1)μM^(−1) and 14.86 mg g^(−1)μM^(−1),respectively.The experimental data are suitable for Langmuir isotherm and Pseudo-secondorder kinetic models,which correspond to monolayer chemisorption.Thermodynamic analysis indicates that the adsorption process is spontaneous and endothermic.Moreover,the removal percentages of MG and Pb^(2+)by the ORCF could remain above 90%after five cycles,implying that the ORCF is an efficient adsorbent with good adsorption ability and cycling stability.
文摘The stability of the photoluminescence (PS) has evidently improvedby HNO3 chemical oxidation The PL intensity and peak wavelength of PS were changed with theHNO3 of HNO3 concentration and oxidation time. Being different from other oxidation time. Being different from other oxidized ways, the PSoxidized by HNO3 remains remains sensitive to adsorbates. FTTR spectroscopic data suggest that these phenomena are attributed to the presence of HSi(SiaO30a)(a≤3)layer on PS surface.
