Surface Modification Of Carbon Nanospheres And Their Adsorption-Photocatalytic Properties

Adsorption-photocatalytic degradation technology is identified as the most promising environmental treatment method which has attracted much attention.Among all kinds of adsorbent materials,carbon-based materials have good water remediation performance and environmental friendliness,but they are rarely used in the adsorption-photocatalytic degradation of organic dyes due to the weak adsorption performance for organic dyes.This academic dissertation on the basis of the review and analysis related works,we put forward the new thought and avenues of surface modification for carbon nanospheres,"the surface modification and adsorption-photocatalytic properties of carbon nanospheres"as research subject and systematically summarizes the research work during the study for my master's degree.The main research and results are summarized as follows:?1?A new method of surface modification of C nanospheres by ternary semiconductor Cu₃SnS₄?CTS?was proposed.CTS@C nanocomposite structure was prepared by coupling CTS and C nanospheres through a facile two-step hydrothermal reaction,and the adsorption property of the complex structure on anionic dye methyl orange?MO?was studied systematically.The results showed that the adsorption capacity of MO by CTS@C was significantly higher than pure CTS nanoparticles and C nanospheres,and showed a pH-sensitive behavior.Under acidic conditions?pH=5.0?the adsorption capacity was about 65.99 mg g^-1,and alkaline conditions?pH=11.0?was only about 8.11 mg g^-1.The better adsorption performance of CTS@C nanocomposites could be ascribed to the coupled CTS,which would exhibit acidic in aqueous solution and thus make more positive charged active sites on the surface of CTS@C to available for adsorption anion dye,electrostatic interaction is the main factor to improve the adsorption performance of CTS@C.?2?CTS have been widely applied in photocatalytic and photoelectric converting due to its excellent photoelectric properties,after investigating the adsorption properties of CTS@C nanocomposite structure,the adsorption-photocatalytic degradation property of CTS@C nanocomposite structure were further studied.The result showed that at pH=7.5,compared with the C nanospheres which almost no adsorption-photocatalytic performance,the adsorption-photocatalytic removal rate of MO by CTS@C reached 87%within 60 min.The highest efficiency of adsorption-photocatalysis for MO by CTS@C can be attributed to follows:Firstly,the narrow band gap CTS has a high response to visible light.Secondly,the large specific surface area of CTS@C can effectively increase the active site.Thirdly,the synergistic effect between CTS and carbon nanospheres.?3?A new method of surface modification of C nanospheres by N,N-dimethylformamide?DMF?was proposed.DMF was introduced to treat the surface of carbon nanospheres?CNPs?through hydrothermal method,and the adsorption properties of DMF-CNPs on cationic and anionic dyes were studied.The results showed that DMF-CNPs and pure carbon nanospheres had opposite potentials in the solution with a pH of 5.0 after DMF treatment,which were+14.36±0.47 and-20.70±0.76 mV,respectively.DMF-CNPs exhibited higher selective adsorption for cationic dyes than carbon nanospheres,and the adsorption removal rate for rhodamine B with initial concentration of 10 mg L^-11 reached more than 99%within 10 minutes.The work can provide a new method and approach for the design and preparation of highly selective adsorbent materials.