A recyclable catalyst made of two-dimensional gold-loaded cellulose paper for reduction of 4-nitrophenol

Two-dimensional gold nanostructures with controlled edge length and thickness were synthesized into polygonal shapes categorized as smooth/jagged-edged and single/multiple-layered nanosheets. Despite their micrometer-scaled lateral dimension, the high catalytic activity of the 2D Au nanostructures was observed in the reduction reaction of 4-nitrophenol to 4-aminophenol in the presence of NaBH₄. We studied the dependability of the catalytic performance on the edge area by examining the relationship between rate constants and catalytically active area of single-layered, jagged-edged, and multiply stacked 2D Au nanostructures. Furthermore, we successfully fabricated a robust and reusable catalyst by incorporating 2D Au nanostructures in a cellulose paper as a flexible substrate through the monolayer assembly and transfer method. The comparative study shows that multiply stacked Au nanosheets on a paper substrate outperformed the other Au nanostructures including nanoparticle.