纳米纤维素-聚乙烯亚胺-聚吡咯复合气凝胶对Cr(Ⅵ)的光催化还原及循环吸附
Photocatalytic reduction and cyclic adsorption of Cr(Ⅵ)by nanocellulose-polyethylenimine-polypyrrole composite aerogel
杨明琰 1蔡晓丹 2陈欣玥 2安琳玉 2邢建宇1
作者信息
- 1. 长安大学 水利与环境学院,西安 710054;旱区地下水文与生态效应教育部重点实验室,西安 710054;水利部旱区生态水文与水安全重点实验室,西安 710054
- 2. 长安大学 水利与环境学院,西安 710054
- 折叠
摘要
吸附与光催化还原相结合可以在光照条件下将 Cr(Ⅵ)还原成低毒性的 Cr(Ⅲ)并固定在吸附材料中,是一种很有前景的铬污染治理方法.本文以纳米纤维素-聚乙烯亚胺气凝胶(CPA)为骨架,通过吡咯原位氧化聚合制得纳米纤维素-聚乙烯亚胺-聚吡咯(CPP-F)光敏感复合气凝胶.采用SEM、FTIR、UV-vis、XPS对气凝胶进行表征.通过黑暗及光照条件的对比,研究了CPP-F复合气凝胶对Cr(Ⅵ)的吸附、光催化原位还原及循环吸附性能,并对其循环吸附机制进行了分析.结果表明:CPP-F为黑色、结构均匀稳定的多孔气凝胶,在紫外、可见光和近红外区域均有较强的光吸收.负载Cr(Ⅵ)的CPP-F经光照处理后,Cr(Ⅲ)含量由黑暗条件下 29.76wt%上升至 72.33wt%,其还原率是黑暗条件下的 2.43倍,表明聚吡咯(PPy)具有优异的光催化性能,光照处理可促进Cr(Ⅵ)的原位还原.经过 6次循环吸附,光照处理下CPP-F对Cr(Ⅵ)的循环吸附量比黑暗处理高64.97%,其原因可能是光催化还原产生的Cr(Ⅲ)为Cr(Ⅵ)提供了新的吸附位点,促进了Cr(Ⅵ)的循环吸附.吸附-光催化还原-循环吸附相结合的方法比单一吸附法更具优势,在Cr(Ⅵ)污染治理方面有很大的应用潜力.
Abstract
The combined method of adsorption-reduction is a promising method for chromium pollution control.In this paper,nanocellulose-polyethylenimine-polypyrrole(CPP-F)photosensitive composite aerogel was prepared by in-situ oxidation polymerization of pyrrole using nanocellulose-polyethylenimine aerogel(CPA)as skeleton.The aerogel was characterized by SEM,FTIR,UV-vis and XPS.The adsorption,in-situ reduction and cyclic adsorption properties of CPP-F composite aerogel on Cr(Ⅵ)were studied by comparing the dark and light conditions,and the cyclic adsorption mechanism was analyzed.The results show that CPP-F is a black porous aerogel with uniform and stable structure,and has strong light absorption effect in ultraviolet,visible and near infrared region.After light treatment,Cr(Ⅲ)content in Cr(Ⅵ)loaded CPP-F increase from 29.76wt%under dark conditions to 72.33wt%,and its reduction rate is 2.43 times that of dark conditions,indicating that polypyrrole(PPy)has excellent photocatalytic performance,and light treatment can promote the in-situ reduction of Cr(Ⅵ).After 6 cycles of adsorption,the cyclic adsorption capacity of Cr(Ⅵ)by CPP-F under light treatment is 64.97%higher than that under dark treatment,indicating that photocatalytic reduction of Cr(Ⅲ)provides a new adsorption site for Cr(Ⅵ)and realizes the cyclic adsorption of Cr(Ⅵ).The combination of adsorption-photocatalytic reduction-cyclic adsorption has more advantages than adsorption method,and has great application potential in Cr(Ⅵ)pollution control.
关键词
光催化/纳米纤维素/气凝胶/聚吡咯/Cr(Ⅵ)/光还原/循环吸附Key words
photocatalytic/nanocellulose/aerogel/PPy/Cr(Ⅵ)/photoreduction/cyclic adsorption引用本文复制引用
基金项目
陕西省重点研发计划(2021SF-443)
出版年
2024
NETL
NSTL
万方数据