One-step synthesis of gold nanocatalysts on a microstructured paper matrix for the reduction of 4-nitrophenol

The one-step synthesis of gold nanoparticles (AuNPs) was achieved, in situ, on a microstructured paper composite that consisted of ceramic fibers which acted as the main frame with zinc oxide (ZnO) whiskers being used as the selective support for the AuNPs. Initially, ZnO whiskers were incorporated into a ceramic paper matrix using a high-speed and low-cost papermaking technique, and the AuNPs were then synthesized onto the embedded ZnO whiskers via a simple soaking treatment using an aqueous solution of tetrachloroauric acid (HAuCl₄). The as-prepared hybrid material has the appearance of paperboard and is denoted as AuNPs@ZnO paper. It was lightweight, flexible, sufficiently strong and easy-to-handle in practical use, and possessed a paper-like porous microstructure. In the liquid-phase reduction process of 4-nitrophenol, the AuNPs@ZnO paper demonstrated excellent catalytic performance compared with conventional Au/ZnO catalyst powders. This suggests that the unique paper structure, which has an open pore system throughout the structure, promotes the efficient transport of the reactants to the surfaces of the highly effective AuNPs. Thus, this AuNPs@ZnO paper is expected to be a promising catalytic material having a high degree of practical utility and catalytic efficiency.