Combination Mechanism and Enhanced Visible-Light Photocatalytic Activity and Stability of CdS/g-C3N4 Heterojunctions

作     者：Huanyan Xu Licheng Wu Liguo Jin Kejia Wu 

作者机构：School of Materials Science and Engineering Harbin University of Science and Technology Harbin 150040 China 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2017年第33卷第1期

页      面：30-38页

核心收录：

学科分类：081705[工学-工业催化] 0806[工学-冶金工程] 0817[工学-化学工程与技术] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0703[理学-化学] 0802[工学-机械工程] 0702[理学-物理学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：financially supported by the National Natural Science Foundation of China(Nos.51404083 and 21273060) the Program for New Century Excellent Talents in Heilongjiang Provincial Universities(No.1253-NCET-010) the Natural Science Foundation of Heilongjiang Province,China(No.E2015065) 

主　　题：CdS/g-C3N4 Heterojunctions Photocatalytic stability Photocatalytic mechanism 

摘      要：In this study, CdS/g-C3N4 （CSCN） heterojunctions were in situ fabricated with a large amount of CdS nanoparticles anchored on g-C3N4 nanosheets, A wet chemical method was developed for the first time to determine the actual content of CdS in CSCN composites. X-ray diffraction （XRD）, Fourier transform infrared spectra （FFIR）, high-resolution transmission electron microscopy （HRTEM） and UV-vis diffuse reflectance spectra （DRS） were employed to characterize the composition, structure and optical prop- erty of CSCN composites. Based on the is0electric point （liP） analysis of g-C3N4, a conclusion was obtained on the combination mechanism between CdS nanoparticles and g-C3N4 nanosheets. The photocatalytic activity of CSCN composites was much better than those of individual CdS and g-C3N4 for the degrada- tion 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 CdS, implying that the photocorrosion of CdS 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 CdS, the possible photocatalvtic mechnism was discussed.