Metal-Doped Carbon-Supported/Modified Titanate Nanotubes for Perfluorooctane Sulfonate Degradation in Water：Effects of Preparation Conditions, Mechanisms, and Parameter Optimization

作     者：Zhu, Yangmo Xu, Tianyuan Zhao, Dongye 

作者机构：Environmental Engineering Program Department of Civil and Environmental Engineering Auburn University AuburnAL36849 United States School of Resource and Geosciences China University of Mining and Technology Jiangsu Xuzhou221116 China Department of Civil Construction and Environmental Engineering San Diego State University 5500 Campanile Drive San DiegoCA92182 United States 

出 版 物：《SSRN》 

年 卷 期：2022年

核心收录：

主　　题：Activated carbon 

摘      要：Metal-doped, activated carbon (AC) supported titanate nanotubes (Me/TNTs@AC) have been shown promising for photocatalytic degradation of per- and polyfluoroalkyl substances (PFAS). However, the preparation recipe of these adsorptive photocatalysts has not yet been optimized in terms of type and content of precursor materials and the metal dopants as well as synthesizing conditions. To address this knowledge gap, we prepared TNTs@AC based on a commercial TiO2 and six different ACs at varying AC:TiO2 ratios and under different hydrothermal conditions. In addition, a suite of dopant metal ions, including Fe3+, Bi3+, Ga3+, In3+, Co2+, Cu2+, and Mn2+, were compared to gauge their effect on the material photoactivity. Moreover, the effect of the calcination temperature was also tested. The photocatalytic performance of Me/TNTs@AC was evaluated based on their effectiveness in defluorination of pre-sorbed perfluorooctane sulfonic acid (PFOS) after 4-h UV irradiation. Based on the experimental results, the highest photocatalytic mineralization efficiency (66.2%) of PFOS was achieved using Ga/TNTs@AC prepared under the following conditions: Filtrosorb-400® = 50 wt.%, Ga = 2 wt.%, hydrothermal treatment temperature = 130 ℃, hydrothermal duration = 72 h, and calcination temperature = 550 ℃. To understand the underlying mechanisms, selected materials were characterized via X-ray diffraction, the BET surface area and pore volume, UV-vis diffuse reflectance spectrometry, and photoluminescence. The results revealed that the superior photoactivity of Ga/TNTs@AC is attributed to the Ga-facilitated formation of pure crystallized anatase phase during the calcination, high UV light absorption, formation of microscale hybrid AC-anatase-Ga phases, and oxygen defects induced by Ga3+. The information can facilitate preparation and optimization of composite photocatalysts for efficient adsorption and photocatalytic degradation of PFAS in water. © 2022, The Authors. All rights reserved.