摘要
采用水热法将GO和TNTs复合,制备了一种新型还原氧化石墨烯/二氧化钛纳米管复合材料(r GO/TNTs)。采用BET、XRD、FT-IR对制备的材料进行了表征,并研究了r GO/TNTs协同降解水中Cr(Ⅵ)和苯酚的性能。结果表明,在Cr(Ⅵ)和苯酚共存二元体系中,r GO/TNTs对Cr(Ⅵ)和苯酚的光催化降解反应动力学常数约为其各自单体系的6.3倍和1.2倍;低pH可促进Cr(Ⅵ)和苯酚的去除,而共存无机阴离子对其具有抑制作用。·OH和空穴主导苯酚降解,光生电子直接还原Cr(Ⅵ)。
In this study,a novel reduced graphene oxide/titanium dioxide nanotube composite material(rGO/TNTs)was successfully synthesized by the combination of GO and TNTs through hydrothermal reaction. Then the prepared samples of rGO/TNTs were characterized by BET,XRD,and FT-IR,respectively. Finally,the prepared nanotubes were applied to degrade the Cr(Ⅵ) and phenol from water synergistically. The enhanced photocatalytic removals of coexistent Cr(Ⅵ) and phenol by rGO/TNTs were observed in binary systems,and their kinetic constants were about6.3 and 1.2 times those in the respective single systems. The low pH were found to improve the removals of Cr (Ⅵ)and phenol,while the coexisting inorganic anions had negative effects. In addition,hydroxyl radical and holes were proved to dominate the phenol degradation,whereas photogenerated electrons directly reduced the Cr(Ⅵ).
引文
[1] Venturini J,Bonatto F,Guaglianoni W C,et al. Cobalt-doped titanium oxide nanotubes grown via one-step anodization for water splitting applications[J]. Applied Surface Science,2019,464:351-359.
[2] Antolini E. Photo-assisted methanol oxidation on Pt-TiO2catalysts for direct methanol fuel cells:A short review[J]. Applied Catalysis B:Environmental,2018,237:491-503.
[3]李娜,张立新,黄云杰,等.还原氧化石墨烯-TiO2纳米管复合光催化剂的制备及其对CO2的光催化还原性能[J].化工环保,2015,35(2):199-203.
[4]李超,李红艳,崔建国,等. GR/TNT复合光催化剂的制备及其降解苯酚的性能研究[J].环境工程,2018,36(3):1-7.
[5] Wu Chuandong,Liu Jiemin,Liu Shihua,et al. Assessment of the health risks and odor concentration of volatile compounds from a municipal solid waste landfill in China[J]. Chemosphere,2018,202:1-8.
[6] Liu Fenghui,Yu Jie,Tu Guangyuan,et al. Carbon nitride coupled Ti-SBA15 catalyst for visible-light-driven photocatalytic reduction of Cr(Ⅵ) and the synergistic oxidation of phenol[J]. Applied Catalysis B:Environmental,2017,201:1-11.
[7] Kusiak-Nejman E,Wanag A,Kowalczyk L,et al. Graphene oxideTiO2and reduced graphene oxide-TiO2nanocomposites:Insight in charge-carrier lifetime measurements[J]. Catalysis Today,2017,287:189-195.
[8] Perera S D,Mariano R G,Khiem V,et al. Hydrothermal synthesis of graphene-TiO2nanotube composites with enhanced photocatalytic activity[J]. ACS Catalysis,2012,2(6):949-956.
[9] Liu Hui,Dong Xiaonan,Wang Xichao,et al. A green and direct synthesis of graphene oxide encapsulated TiO2core/shell structures with enhanced photoactivity[J]. Chemical Engineering Journal,2013,230(16):279-285.
[10] Wang M, Han J, Xiong H, et al. Yolk@shell nanoarchitecture of Au@r-GO/TiO2, hybrids as powerful visible light photocatalysts[J].Langmuir,2015,31(22):6220-6228.
[11]李瑞亿,陈玉青,何伟娜,等.含Ti3+的TiO2制备及光催化降解有机污染物研究[J].工业水处理,2018,38(1):70-73.