中图分类号： 0636.1⁺1 文献标识码：A DOI：10.7535/hbkd.2025yx03004

Catalytic reduction of methylene blue using cellulose-based silver-loaded hydrogels

GAO Kairu，ZHANG Xinyao，CUI Maoqi，YUAN Miao，LIU Shaojie （Schoolof Chemical and Pharmaceutical Engineering，Hebei Universityof Science and Technology， Shijiazhuang，Hebei O50o18，China）

Abstract：In viewof theproblem thatitisdificult tobalance the highcatalyticactivityandeasyrecoveryof silver nanoparticles （ Ag NPs）catalyst in the catalytic reduction of methylene blue（MB），a cellulose-based silver-loaded hydrogel （TOC-CMC-Ag）was prepared and its catalytic reduction performance to MB was studied.Firstly，TOC-CMC hydrogels were prepared with oxidized cellulose（TOC）and carboxymethylcelulose（CMC）as raw materials and epichlorohydrin（ECH）as cross-linkingagent.Theefectof CMCsubstitution degree ontheirswelingandadsorption propertieswasstudied.Then， TOC-CMC- Ag was prepared by in-situ reduction method using the TOC-CMC hydrogel with the best adsorption performance as thecarrier.Theproductionwas characterized by transmision electron microscopyand X-rayphotoelectron spectroscopy.

Finally，the catalytic reduction performance of TOC-CMC- on MB was studied. The results indicate that TOC-CMC-Ag can completely reduce MB within4minutes.After7catalyticcycles，MBcouldstillbecompletelyreduced：The prepared silver loaded hydrogel with highcatalyticactivityandeasyrecovery providesanew wayforthedevelopment of catalyticreduction catalyst with excellent comprehensive performance.

Keywords：polymer composites；celulose-based hydrogels；silver nanoparticles；catalytic reduction; methylene blue

亚甲基蓝（methylene blue，MB）是常见的水溶性染料之一，在水性介质中以离子形式存在，因含有偶氮、杂环和芳环等基团，MB具有较大的毒性[1-4]。混凝、吸附和催化还原是去除 MB 的常用方法[5]。其中，催化还原法因其优异的去除效果受到广泛关注。

金属纳米颗粒因具有大比表面积、强电子转移能力、高催化活性等特点，被广泛应用于催化还原MB，成为一种常用的催化剂[6]。其中，银纳米颗粒（AgNPs）因具有价格低廉、消光系数高等优势而受到广泛关注[7-11]。但是，Ag NPs 的高表面自由能和不稳定性，使其在液相反应中容易因团聚而失活[12]，且难以回收。利用载体负载 AgNPs 是解决上述问题的有效方法[13]。常用的载体有无机材料和有机聚合物[14-19]。然而，负载型银催化剂虽然回收方便，但反应速率和催化活性往往较低。水凝胶是一种亲水性材料，具有立体网状结构，可以在水中吸附、滞留大量水分，但又不溶于水[20-26]。此外，水凝胶结构中亲水基团的存在可促进离子转化，用其负载 AgNPs 可实现在水中的拟均相催化[26]。

目前，制备催化活性高、反应速度快、循环性能好的载银水凝胶仍面临挑战。由2，2，6，6-四甲基哌啶-1-氧自由基（TEMPO）作为催化剂制备的氧化纤维素（oxidized cellulose，TOC）含有大量羧基，具有稳定性好、对阳离子吸附能力强等优点。将TOC作为骨架引人水凝胶中，可以赋予水凝胶大量吸附位点，并保持稳定性;用羧甲基纤维素（carboxymethyl cellulose，CMC）作为水凝胶网络中的亲水性填料，可以进一步增加溶胀性和吸附速度。基于此，本文以环氧……