Polythiourea-Immobilized Gold Nanoparticles on Filter Paper for Boosting Catalytic Conversion Efficiency and Stability

Gold nanoparticles (AuNPs) have outstanding catalytic properties, whereas their broader application is hindered by limited charge transport and stability. In this work, we present a simple and rapid synthesis method for immobilizing AuNPs onto filters using polythiourea, aimed at facilitating charge transport and enhancing the catalytic conversion of 2-nitrophenol in aqueous solutions. The results show an obvious enhancement in the catalytic performance of the AuNPs when immobilized onto the filter paper with polythiourea, reducing the complete conversion time from 14 min to 150 s. The optimal addition amount of polythiourea is 5.0 mL. Additionally, the kinetics and recyclability of the system were investigated; it was observed that even after 15 cycles of testing, the catalytic complete conversion time of the AuNPs immobilized on the filter with polythiourea maintained consistently at 150 s. These findings suggest a promising strategy for extending the functional lifespan of AuNPs while offering a platform for catalytic reactions.