Multifunctional self-assembly 3D Ag/g-C3N4/RGO aerogel as highly efficient adsorbent and photocatalyst for R6G removal from wastewater

Highlights: • Multifunctional 3D Ag/g-C₃N₄/RGOA is facilely prepared by one-pot hydrothermal method. • This composite aerogel exhibits excellent adsorption and photocatalytic degradation performance. • The prepared 3D Ag/g-C₃N₄/RGOA is recyclable and recycle conveniently in the application of aqueous systems. At present, there is an urgent need to develop a highly efficient adsorbent and photocatalyst with photodegradability under visible light for the removal of dye molecules in wastewater. Herein, the multifunctional three-dimensional Ag/g-C₃N₄/reduced graphene oxide aerogel (Ag/g-C₃N₄/RGOA) has been successfully prepared by a simple "one-pot" hydrothermal method, which exhibits three kinds of improved properties including excellent surfaced-enhanced Raman scattering (SERS) activity, highly efficient adsorption and photocatalytic activity. The composite aerogel presents 3D porous network structure. Importantly, the composite aerogel exhibits excellent adsorption and photocatalytic performance with adsorption rate of 44% and degradation rate of 93%. This is mainly attributed to the synergistic effect of Ag NPs, g-C₃N₄ and RGO, which promotes the separation of photogenerated electrons and holes. In addition, the 3D porous network structure is conducive to the utilization of visible light and the transfer of photogenerated electrons. Furthermore, Ag/g-C₃N₄/RGOA exhibits excellent SERS activity with a detection limit of 1 × 10⁻⁷ M for R6G molecules. The SERS performance has been utilized to monitor the process of adsorption and photodegradation of R6G by the composite aerogel. In this research, the designed multifunctional aerogel may become an attractive material for the detection and removal of dyes in wastewater.