Pany Biswajit, Majumdar Amrito Ghosh, Bhat Suresh, Si Satybrata, Yamanaka Junpei, Mohanty Priti S
School of Chemical Technology, Kalinga Institute of Industrial Technology (KIIT), Deemed to be University, Bhubaneswar, 751024, India.
School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT), Deemed to be University, Bhubaneswar, 751024, India.
Heliyon. 2024 Feb 22;10(5):e26244. doi: 10.1016/j.heliyon.2024.e26244. eCollection 2024 Mar 15.
We have showcased the potential of polymerized hydrogels (PGMs) with uniform-sized stimuli-responsive microgel particles as promising alternatives to prevent aggregation in solution based nanoparticle systems. In the current work, we implemented the PGM concept by embedding anionic stimuli-responsive microgels (PNIPAM-co-AAc)-silver (Ag) hybrids within a hydrogel matrix. These PGM@AgNP hybrid materials are used as catalysts for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of sodium borohydride. UV-VIS spectroscopy is used for studying catalytic activity. In the solution based system, the complete reduction of 4-NP to 4-AP took 30 minutes with pure Ag nanoparticles, 24 minutes with PNIPAM-Ag hybrid (Neutral) microgels and 15 minutes with PNIPAM-co-AAc-Ag (Anionic) hybrid microgels. In contrast PGM containing PNIPAM-co-AAc-Ag hybrids achieved full reduction in just 15 minutes, along with a 3-minute induction period. For pure Ag nanoparticles, the first-order rate constant is found to be 0.25 min, for PNIPAM-Ag hybrid (Neutral), it is 0.21 min and for PNIPAM-co-AAc-Ag (Anionic), it is 0.5 min where as for PGM containing anionic microgel hybrids it is found to be 0.8 min. Furthermore, the reusability of the PGM-Ag (anionic) materials for catalytic activity remains unaltered even after several washings. In summary, our study highlights the effectiveness of PGM@AgNP materials as efficient catalysts for the reduction of 4-nitrophenol to 4-aminophenol, indicating their versatile potential in various catalytic applications.
我们已经展示了具有尺寸均匀、对刺激有响应的微凝胶颗粒的聚合水凝胶（PGM）作为基于溶液的纳米颗粒系统中防止聚集的有前途的替代物的潜力。在当前工作中，我们通过将阴离子刺激响应性微凝胶（PNIPAM-co-AAc）-银（Ag）杂化物嵌入水凝胶基质中来实现PGM概念。这些PGM@AgNP杂化材料用作在硼氢化钠存在下将4-硝基苯酚（4-NP）还原为4-氨基苯酚（4-AP）的催化剂。紫外-可见光谱用于研究催化活性。在基于溶液的系统中，纯银纳米颗粒将4-NP完全还原为4-AP需要30分钟，PNIPAM-Ag杂化（中性）微凝胶需要24分钟，而PNIPAM-co-AAc-Ag（阴离子）杂化微凝胶需要15分钟。相比之下，含有PNIPAM-co-AAc-Ag杂化物的PGM仅在15分钟内就实现了完全还原，还有3分钟的诱导期。对于纯银纳米颗粒，一级速率常数为0.25分钟，对于PNIPAM-Ag杂化（中性）为0.21分钟，对于PNIPAM-co-AAc-Ag（阴离子）为0.5分钟，而对于含有阴离子微凝胶杂化物的PGM为0.8分钟。此外，PGM-Ag（阴离子）材料的催化活性可重复使用性即使经过多次洗涤也保持不变。总之，我们的研究突出了PGM@AgNP材料作为将4-硝基苯酚还原为4-氨基苯酚的高效催化剂的有效性，表明它们在各种催化应用中的多功能潜力。
