Comparison of the catalytic properties of Au nanoparticles supported on different two-dimensional carriers

Abstract

Choosing a suitable two-dimensional (2D) nanomaterial as a carrier for noble metals is crucial for improving the catalytic performance and reducing the cost of nanocatalysts. In this study, we used ultrathin porous g-C3N4 nanosheets (g-C3N4-NS) as a carrier with gold nanoparticles (Au NPs) anchored on the surface. The ultrathin g-C3N4-NS was advantageous as a carrier because of its large specific surface area, abundant in-plane holes, and low cost. For comparison, 2D TiO2 nanosheets (NS), graphene oxide (GO) NS, and bulk g-C3N4 (g-C3N4-B) were also tested as carriers for the immobilization of Au NPs. Au NPs supported on different carriers were employed as catalysts for the reduction of 4-nitrophenol. The rate constant was calculated as 16.21 × 10−3 s−1 for the Au/g-C3N4-NS nanocatalyst, which was 11.4 and 42.1 times higher than those for the Au/TiO2 and Au/GO nanocomposites, respectively. Au/g-C3N4-NS exhibited excellent catalytic activity during the conversion of 4-nitrophenol with a turnover frequency of 1648 h−1. The as-prepared Au/g-C3N4-NS nanocatalyst also exhibited good catalytic performance during the reduction of 2-nitrophenol and 3-nitrophenol.