Gold Nanoparticles Adsorbed on Graphene as Nanozymes for the Efficient Elimination of Dye Pollutants

Abstract

Over the past several decades, the design and development of nanomaterials with intrinsic enzyme-mimicking activities (nanozymes) have attracted increasing attention. Herein, we present a simple strategy for the construction of graphene–gold nanoparticle (Graphene/Au-NPs) nanozymes via a one-step hydrothermal reaction, which can act as a highly efficient dye scavenger with the synergetic effect of adsorption and degradation. The as-prepared nanocomposites can overcome the intrinsic drawbacks of single-component Au-NPs, such as ease of aggregation and cannot capture substrates effectively. In our catalytic system, Graphene/Au-NPs can readily adsorb organic dyes onto their surfaces, catalyze H2O2 to generate •OH radicals, and then exhibit outstanding removal performance toward different organic dyes. Their catalytic mechanism is analogous to that of natural enzymes, in which the specific high catalytic efficiency depends mainly on their capacity to keep the substrate close to the active site of the enzyme. Collectively, our work may pave the way to apply multifunctional nanozymes in different research areas, such as environmental treatment, sensing, and biotechnology.