Solid Br?nsted acidity boosts adsorption reactivity of nano-adsorbent for water decontamination

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外文摘要：Despite the development of various Lewis acidic nano-adsorbents for fluoride removal through inner-sphere coordination,strong competition for hydroxyl ions still hinders efficient water defluoridation.In addition,the critical issue of polysilicate scaling that results from the ubiquitous silicates must be addressed.To tackle these issues,an alternative approach to enhancing adsorption reactivity by modifying nano-adsorbents with dual Lewis and Brønsted acidity is proposed.The feasibility of this approach is demonstrated by growing zirconium phosphate(ZrP)inside a gel-type anion exchanger,N201,to produce nanocomposite ZrP@N201,in which the confined ZrP contained an otherwise metastable amorphous phase with Lewis acidic Zr4+sites and Brønsted acidic monohydrogen phosphate groups(-O3POH).Compared with the Lewis acidic nano-zirconium oxide analog(HZO@N201),ZrP@N201 exhibited a greatly improved adsorption capacity(117.9 vs.52.3 mg/g-Zr)and mass transfer rate(3.56 × 10-6 vs.4.55 × 10-7 cm/s),while bulk ZrP produced a thermodyna-mically stable α-phase with Brønsted acidity that exhibited negligible adsorption capability toward fluoride.The enhanced defluoridation activity of ZrP@N201 is attributed to Brønsted acidity and the increased outer electron density of Zr4+sites,as corroborated using XPS and solid-state NMR analysis.Moreover,Brønsted acidity strengthens the resistance of ZrP@N201 to silicate,allowing its fiill regeneration during cyclic defluoridation.Column tests demonstrated 3-10 times the amount of clean water from(waste)for ZrP@N201 as compared to both HZO@N201 and the widely used activated aluminum oxide.This study highlights the potential of developing nano-adsorbents with dual acidities for various environmental remediation applications.

外文关键词：

NanocompositeSelective adsorptionFluoride removalDual Lewis and Brønsted acidityRegeneration

作者：

Sikai Cheng、Zhixian Li、Kaisheng Zhang、Qingrui Zhang、Xiaolin Zhang、Bingcai Pan

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作者单位：

State Key Laboratory of Pollution Control and Resource Reuse,School of the Environment,Nanjing University,Nanjing 210023,China

Environmental Materials and Pollution Control Laboratory,Institute of Solid State Physics,HFIPS,Chinese Academy of Sciences,Hefei 230031,China

State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,China

Hebei Key Laboratory of Heavy Metal Deep-remediation in Water and Resource Reused,Qinhuangdao 066004,China

Research Center for Environmental Nanotechnology(ReCENT),Nanjing University,Nanjing 210023,China

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基金：

National Key Research and Development Program of ChinaNational Natural Science Foundation of China

项目编号：

2022YFC320530022122604

出版年：

2024

DOI：

10.1007/s11783-024-1841-2

环境科学与工程前沿

高等教育出版社

环境科学与工程前沿

影响因子：0.545

ISSN：2095-2201

年,卷(期)：2024.18(7)