A portable holey carbon nitride/3D Ag facilely self-assembled on copper sheet for dramatically enhanced SERS and photocatalytic performance

In this work, the protonated holey carbon nitride (ph-CN) on hydroxylated copper sheet (Cu/ph-CN) with effective interfacial contact is prepared via electrostatic self-assembly strategy. Subsequently, a novel bifunctional substrate is constructed by anchoring of 3D Ag (Ag cube and Ag pyramid) mainly embedded within the cavities of Cu/ph-CN (Cu/ph-CN/Ag). Results demonstrate that the Cu/ph-CN/Ag substrate displays a significant SERS and photocatalytic performance for p-aminobenzenethiol (PATP) due to the strong synergistic effect among Cu, ph-CN and 3D Ag. Specifically, the Cu/ph-CN/Ag substrate exhibits a high SERS sensitivity for PATP which shows a low detection limit of 8.96 × 10−11 mol·L−1 with enhancement factor of 1.31 × 106. Also, the PATP in actual water samples can still be identified even at a lower concentration of 1 × 10−9 mol·L−1. In addition, the photocatalytic degradation efficiency of the Cu/ph-CN/Ag substrate for PATP can be as high as 99.51% within 20 min, and the rate constant (k) is up to 0.2525 min−1, which is about ∼33 times that of the CN/Ag system. In addition, this substrate shows high stability and satisfactory recyclability. Thus, it is expected to be used as an eminent bi-functional material for highly sensitive detection and efficient photocatalytic degradation of other environmental pollutants in wastewater.