Highly Efficient Paper‐Based 2D Catalytic System: Optimization of Light‐Induced Synthesis and Catalytic Function of Supported Gold Nanoparticles

Light‐induced synthetic conditions are optimized to control the fabrication of gold nanoparticles (AuNPs) at room temperature. This approach utilizes a broadband light source with an intensity of ≈100 mW cm ^–2 mimicking daily sunlight, which enhances the direct formation of AuNPs using four different reducing agents under ambient conditions. After identifying the best reducing agent, a series of stable AuNPs is systematically prepared by controlling the ratios of gold ions and the reducing agent. The resulting AuNPs are then deposited onto filter paper via a simple dip‐coating method to serve as a 2D heterogeneous catalyst in the aerobic homocoupling of arylboronic acid. The general reaction conditions are also optimized to achieve high reactivity and selectivity as well as recyclability. In addition, the light‐enhanced catalytic activity of the resulting 2D papers is evaluated to reveal the contribution of their strong surface plasmon resonance. Furthermore, the plasmonic papers are utilized in oxidation reactions to demonstrate their versatility as a 2D catalyst. Thus, developing a green and simple approach to improve the formation and loading efficiency of plasmonic NPs onto paper‐derived substrates, and understanding their structural and physicochemical features will enable the advancement of highly effective and practical 2D‐based heterogeneous catalytic systems.