Facile fabrication and the bifunctionality of dendritic Ag nanoparticles mediated by sulfhydryl porphyrin anchored on TiO2-Ag coated copper sheet

Abstract

In order to sensitively detect and degrade organic toxics in real water samples, the design and fabrication of a cost-effective self-cleaning sensor will be vital in practical application. Herein, dendritic Ag nanoparticles were formed on the TiO2-Ag coated copper sheet by means of the induction of the mercaptoporphyrin (SP), and thus a new “plug and play” sandwich-like Cu/TiO2-Ag/SP/Ag (C/T-A/SP/A) composite sheet was constructed. The structure, morphology and composition of the C/T-A/SP/A were characterized by XRD, SEM, TEM and XPS. Furthermore, the Raman activity and photocatalytic performance of the C/T-A/SP/A were investigated with phenol red (PhR) as an analyte. It was found that the electromagnetic effect and electron transfer efficiency in the sheet were greatly improved due to the formed dendritic Ag and the synergistic effect of the silver outside and inside of SP. Subsequently, an extremely sensitive surface enhanced Raman spectroscopy (SERS) response to PhR (as low as 1 × 10−10 mol L−1) and high stability (hardly changed after 30 days) were achieved. Furthermore, the potable C/T-A/SP/A composite sheet displayed excellent photocatalytic activity for the degradation of PhR even though it was repeatedly used for 6 times. The Schottky barrier, synergetic effect and strong oxidizing active species were responsible to the enhanced photocatalytic activity. In particularly, the plug and play C/T-A/SP/A sheet showed sensitive detection and photocatalytic activity towards PhR in wastewater, indicating that the C/T-A/SP/A composite sheet was a convenient and highly efficient self-cleaning sensor for monitoring and degradation of trace PhR in wastewater.