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

作　　者：杨明琰[1,2,3] 蔡晓丹 陈欣玥 安琳玉 邢建宇 YANG Mingyan;CAI Xiaodan;CHEN Xinyue;AN Linyu;XING Jianyu(School of Water and Environment,Chang'an University,Xi'an 710054,China;Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of the Ministry of Education,Chang'an University,Xi'an 710054,China;Key Laboratory of Eco-hydrology and Water Security in Arid and Semi-arid Regions of Ministry of Water Resources,Chang'an University,Xi'an 710054,China)

机构地区：[1]长安大学水利与环境学院,西安710054 [2]旱区地下水文与生态效应教育部重点实验室,西安710054 [3]水利部旱区生态水文与水安全重点实验室,西安710054

出　　处：《复合材料学报》2024年第6期3032-3041,共10页Acta Materiae Compositae Sinica

基　　金：陕西省重点研发计划:农林废弃物木质纤维素类生物质全组分资源化利用技术研究(2021SF-443)。

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。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 

分 类 号：TB332[一般工业技术—材料科学与工程]