复合催化材料纳米氧化铜颗粒(CuO NPs)@纤维素纳米纤丝(CNF)-Si-N(OH)2的制备及其对4-硝基苯酚的催化还原性能

Preparation of catalytic composite copper oxide nanoparticles (CuO NPs)@cellulose nanofiber (CNF)-Si-N(OH)2 and its catalytic reduction of 4-nitrophenol

  • 摘要: 针对目前降解工业废水中4-硝基苯酚(4-NP)的催化剂效率低,催化活性差等问题,以桉木漂白化学浆为原料,通过超微粒研磨机和高压均质机处理制备得到直径50~100 nm和长度1500~2000 nm的纤维素纳米纤丝(CNF),在其表面原位负载纳米氧化铜颗粒(CuO NPs),并通过3-氯丙基三甲氧基硅烷(CPTES)与二乙醇胺(DEA)进行接枝反应制备得到复合催化材料-CuO NPs@CNF-Si-N(OH)2。探讨了DEA添加量对CuO NPs@CNF–Si–N(OH)2的性能影响,采用Zeta电位、FTIR、XRD、XPS、热重分析和形貌分析等方法对复合材料进行了表征。结果表明,CuO NPs被原位还原并成功负载在CNF表面,其直径约为3.84 nm,负载量为3.83wt%,通过硅烷化改性及接枝胺基可提高CuO NPs在复合材料表面的分散性及稳定性,进而增强了其催化活性。CNF基复合催化材料对4-NP的催化还原结果显示,DEA添加量为20wt%下的CuO NPs@CNF-Si-N(OH)2对4-NP催化还原性能最佳,在180 s内可催化还原98.39%的4-NP,且反应符合伪一级动力学模型,表观速率常数为5.50×10−3 s−1,转化效率为1723.41 h−1,研究结果可为高性能催化复合材料的制备提供新思路和新途径。

     

    Abstract: In view of the low efficiency and poor catalytic activity of 4-nitrophenol (4-NP) catalysts for degradation of industrial wastewater, eucalyptus wood bleaching chemical pulp was used as the raw material and treated with ultrafine grinder and high pressure homogenizer to produce cellulose nanofiber (CNF) with the diameter of 50-100 nm and the length of 1500-2000 nm. Then, copper oxide nanoparticles (CuO NPs) were in-situ loaded onto CNF, 3-chloropropyltrimethoxysilane (CPTES) and diethanolamine (DEA) were added for grafting reaction to obtain the catalytic composite of CuO NPs@CNF-Si-N(OH)2. The catalytic composite was characterized with Zeta potential, FTIR, XRD, XPS, thermal gravimetric analysis and morphology analysis. The results show that CuO NPs are in-situ loaded on CNF, and the grafting of amine groups can make the loading of CuO NPs more uniform and stable. In addition, it is also found that CuO NPs@CNF-Si-N(OH)2 show the optimal catalytic performance with 20wt% DEA. Furthermore, 98.39% of 4-NP is catalytically reduced after 180 s, and the reaction fit the pseudo-first order kinetics equation, in which the reacting constant reaches 5.50×10−3 s−1 and the turnover frequency achieves 1723.24 h−1. The composite catalysts of CuO NPs@CNF-Si-N(OH)2 exhibite excellent recycling performance, and 94.42% of 4-NP can be catalytically reduced after a recycling time of 8. The results can provide a new idea and approach for the preparation of high-performance catalytic composite.

     

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