In this study, we report the electron beam (EB)-induced synthesis of a gold nanoparticle (AuNP)-immobilized catalyst on a poly(acrylic acid)-grafted polypropylene (PP- g -PAA) nonwoven fabric and its catalytic activity for pollutant removal. This approach utilizes EB for both the sequential graft polymerization of acrylic acid (AA) and the in situ synthesis of AuNPs via radiolytic reduction, offering a clean and efficient fabrication route. The primary focus of this work is to investigate how the PAA graft amount, which determines the density of anchoring sites for AuNPs, influences their loading and the resulting catalytic efficiency for 4-nitrophenol reduction. Structural and chemical characterization confirmed the successful fabrication of the PP- g -PAA-AuNP catalyst. Results showed that while a higher PAA grafting degree led to an increased loading of AuNPs, the catalytic activity also increased up to a 70% grafting before plateauing. Specifically, the catalysts with grafting degrees of 25%, 50%, 70%, and 90% exhibited rate constants of 0.0372, 0.1200, 0.1633, and 0.1664 min -1 , respectively, indicating similar performance between the 70% and 90% samples. This suggests that catalytic performance is influenced not only by the NP loading amount but also by the accessibility of the catalytically active sites to the reactants. This study demonstrates that EB-induced grafting is a powerful strategy for tailoring the polymer support, enabling precise control over nanoparticle loading and, consequently, catalytic performance for environmental applications. • AuNPs were immobilized on PP fabric via EB-grafting and subsequent EB-reduction. • The grafting degree of PAA determines AuNP loading. • Catalytic performance depends on both AuNP content and site accessibility.
Shin et al. (Sun,) studied this question.