Polymer microgels for the stabilization of gold nanoparticles and their application in the catalytic reduction of nitroarenes in aqueous media

Muhammad Arif; Muhammad Shahid; Ahmad Irfan; Jan Nisar; Weitai Wu; Zahoor H Farooqi; Robina Begum

doi:10.1039/d1ra09380k

Polymer microgels for the stabilization of gold nanoparticles and their application in the catalytic reduction of nitroarenes in aqueous media

RSC Adv. 2022 Feb 10;12(9):5105-5117. doi: 10.1039/d1ra09380k.

Authors

Muhammad Arif^{1

2}, Muhammad Shahid¹, Ahmad Irfan^{3

4}, Jan Nisar⁵, Weitai Wu⁶, Zahoor H Farooqi¹, Robina Begum¹

Affiliations

¹ School of Chemistry, University of the Punjab New Campus Lahore 54590 Pakistan zhfarooqi@gmail.com Zahoor.chem@pu.edu.pk robina.hons@pu.edu.pk.
² Department of Chemistry, School of Science, University of Management and Technology Lahore 54770 Pakistan.
³ Research Center for Advanced Materials Science (RCAMS), King Khalid University P.O. Box 9004 Abha 61413 Saudi Arabia.
⁴ Department of Chemistry, Faculty of Science, King Khalid University P.O. Box 9004 Abha 61413 Saudi Arabia.
⁵ National Centre of Excellence in Physical Chemistry, University of Peshawar Peshawar 25120 Pakistan.
⁶ State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, The Key Laboratory for Chemical Biology of Fujian Province, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University Xiamen Fujian 361005 China.

Abstract

Polymer microgels containing a polystyrene core and poly(N-isopropylmethacrylamide) shell were synthesized in aqueous media following a free radical precipitation polymerization. Au nanoparticles were fabricated into the shell region of the core-shell microgels denoted as P(STY@NIPM) by the in situ reduction of chloroauric acid with sodium borohydride. Various characterization techniques such as transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-visible) and Fourier transform infrared spectroscopy (FTIR) were used for the characterization of Au-P(STY@NIPM). The catalytic potential of Au-P(STY@NIPM) toward the reductive reaction of 4-nitrophenol (4NP) under various reaction conditions was evaluated. The Arrhenius and Eyring parameters for the catalytic reduction of 4NP were determined to explore the process of catalysis. A variety of nitroarenes were converted successfully into their corresponding aminoarenes with good to excellent yields in the presence of the Au-P(STY@NIPM) system using NaBH₄ as a reductant. The Au-P(STY@NIPM) system was found to be an efficient and recyclable catalyst with no significant loss in its catalytic efficiency.