title: Acid-promoted synthesis of UiO-66 for highly selective adsorption of anionic dyes: Adsorption performance and mechanisms.
abstract: UiO-66 was modulated by addition of acetic acid or HCl in the precursor solution. The resulting acetic acid-promoted UiO-66has more regular octahedral structures and high surface areas of 892-1090m2/g. Anionic dyes (methyl orange (MO) and Congo red (CR)) and cationic dyes (methylene blue (MB) and rhodamine B (RhB)) were examined for the selective dye adsorption on various UiO-66. The acid-promoted UiO-66 exhibits an excellent selective adsorption to anionic dyes, where the adsorption capacities of MO and MB are 84.8 and 13.2mg/g, respectively. However, UiO-66 prepared without acid shows similar adsorption to both anionic dye MO (70.4mg/g) and cationic dye MB (67.5mg/g). Mixed dyes (MO/MB and MO/RhB) adsorption on acid-promoted UiO-66 further proves the selective adsorption to anionic dyes. The adsorption mechanism was studied by testing the Zeta potential of acid-promoted UiO-66, and more positive Zeta potential (hydrogen ions) of UiO-66 is beneficial to the anionic dye adsorption.
authors.affiliation: College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China.
authors.forename: Jianhao
authors.initials: J
authors.lastname: Qiu
authors.affiliation: College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Feng
authors.affiliation: College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China.
authors.forename: Xiongfei
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China.
authors.forename: Mingmin
authors.initials: M
authors.lastname: Jia
authors.affiliation: College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China; Jiangsu Key Lab of Biomass-based Green Fuels and Chemicals, Nanjing 210037, China. Electronic address: jfyao@njfu.edu.cn.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Yao
keywords: Acid-promoted synthesis; Anionic dyes; Selective adsorption; UiO-66