Combination Mechanism and Enhanced Visible-Light Photocatalytic Activity and Stability of CdS/g-C3N4 Heterojunctions
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2017年第1期
论文作者：Huanyan Xu Licheng Wu Liguo Jin Kejia Wu
文章页码：30 - 38
摘 要：In this study,CdS/g-C3N4（CSCN） heterojunctions were in situ fabricated with a large amount of Cd S nanoparticles anchored on g-C3N4 nanosheets.A wet chemical method was developed for the first time to determine the actual content of Cd S in CSCN composites.X-ray diffraction（XRD）,Fourier transform infrared spectra（FTIR）,high-resolution transmission electron microscopy（HRTEM） and UV-vis diffuse reflectance spectra（DRS） were employed to characterize the composition,structure and optical property of CSCN composites.Based on the isoelectric point（IEP） analysis of g-C3N4,a conclusion was obtained on the combination mechanism between Cd S nanoparticles and g-C3N4 nanosheets.The photocatalytic activity of CSCN composites was much better than those of individual Cd S and g-C3N4 for the degradation of azo dye Methyl Orange（MO） by 40 min adsorption in the dark followed by 15 min photocatalysis under visible light irradiation.After 5 cycles,CSCN composites still maintained high reactive activity with the MO degradation efficiency of 93.8%,exhibiting good photocatalytic stability.The Cd2+concentration dissolved in the supernatant detected by atomic absorption spectroscopy（AAS） of CSCN composites was lower than that of pure Cd S,implying that the photocorrosion of Cd S could be suppressed via the combination with g-C3N4.Photoluminescence emission spectra（PL） results clearly revealed that the recombination of photogenerated electron-hole pairs in CSCN composites was effectively inhibited due to the formation of heterojunctions.Based on the band alignments of g-C3N4 and Cd S,the possible photocatalytic mechnism was discussed.
Huanyan Xu，Licheng Wu，Liguo Jin，Kejia Wu
School of Materials Science and Engineering,Harbin University of Science and Technology
摘 要：In this study,CdS/g-C3N4（CSCN） heterojunctions were in situ fabricated with a large amount of Cd S nanoparticles anchored on g-C3N4 nanosheets.A wet chemical method was developed for the first time to determine the actual content of Cd S in CSCN composites.X-ray diffraction（XRD）,Fourier transform infrared spectra（FTIR）,high-resolution transmission electron microscopy（HRTEM） and UV-vis diffuse reflectance spectra（DRS） were employed to characterize the composition,structure and optical property of CSCN composites.Based on the isoelectric point（IEP） analysis of g-C3N4,a conclusion was obtained on the combination mechanism between Cd S nanoparticles and g-C3N4 nanosheets.The photocatalytic activity of CSCN composites was much better than those of individual Cd S and g-C3N4 for the degradation of azo dye Methyl Orange（MO） by 40 min adsorption in the dark followed by 15 min photocatalysis under visible light irradiation.After 5 cycles,CSCN composites still maintained high reactive activity with the MO degradation efficiency of 93.8%,exhibiting good photocatalytic stability.The Cd2+concentration dissolved in the supernatant detected by atomic absorption spectroscopy（AAS） of CSCN composites was lower than that of pure Cd S,implying that the photocorrosion of Cd S could be suppressed via the combination with g-C3N4.Photoluminescence emission spectra（PL） results clearly revealed that the recombination of photogenerated electron-hole pairs in CSCN composites was effectively inhibited due to the formation of heterojunctions.Based on the band alignments of g-C3N4 and Cd S,the possible photocatalytic mechnism was discussed.
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