TEM observations were performed on a Zeiss EM 10 Transmission Electron Microscope. FTIR spectra were recorded with a PerkinElmer spectrum 400 FT-IR/FT-NIR spectrometer within the wave range 750–4000 cm−1. X-ray photoelectron spectroscopy (XPS) was carried out on KRATOS XSAM800 X-ray photoelectron spectrometer using Mg as the exciting source. UV–vis absorption and fluorescence spectra were recorded at room temperature on a Hitachi 3100 spectrophotometer and a F-96 spectrophotometer, respectively.
Anodic stripping voltammetry (ASV) experiments were performed using a CHI-660C electrochemical workstation with a conventional three-electrode cell. A glassy carbon electrode (GCE) and the modified electrodes were used as the bare and working electrodes. The auxiliary electrode was a platinum wire. All the potentials quoted in this work were referred to a saturated calomel electrode (SCE) as the reference.