Cary 6400

Using a pH meter (PHS-3C, Shanghai NESA, Shanghai, China), the pH value was determined. Fourier transform infrared (FTIR) spectra (Cary 6400, Agilent, Palo Alto, CA, USA) were used to conduct infrared measurements. The morphologies and microstructures of samples were examined using field emission scanning electron microscopy (FESEM; Quanta 400 FEG, FEI, Portland, OR, USA) and high-resolution transmission electron microscopy (HRTEM; JEOL JEM-2100, Hitachi, Tokyo, Japan). The analysis of thermal stability was performed using thermogravimetry (TG; 6300, Hitachi-chi, Tokyo, Japan). On an X-ray diffractometer (D2 PHASER, Bruker, Karlsruhe, Germany), X-ray diffraction (XRD) patterns were obtained. Utilizing a Thermo scalable 250Xi spectrometer, X-ray photoelectron spectroscopy (XPS) measurements were taken. Utilizing inductively coupled plasma atomic emission spectrometry (ICP-AES; Icap-6300, Thermo Scientific, Portland, OR, USA), the concentration of metal ions was determined.

The instruments used in this study included a pH meter (PHS-3C, INESA, Shanghai, China), a Fourier Transform Infrared Spectrometer (Cary-6400, Agilent, Santa Clara, CA, USA), a Scanning Electron Microscope (S4800, Hitachi, Tokyo, Japan), Thermal Stability Analyser (6300, Hitachi, Tokyo, Japan), an X-ray Photoelectron Spectrometer (Escalab 250 Xi, Thermo Scientific, Waltham, MA, USA), and a coupled plasma atomic emitter (Icap-6300, Thermo Scientific, Waltham, MA, USA).
TCT (99%) was purchased from Shanghai McLean Biochemical Technology Co., Ltd.; EDA, tetrahydrofuran (THF, 99%), and potassium dichromate were provided by Chengdu Cologne Chemical Co., Ltd. (Chengdu, China); HAuCl₄·4H₂O was purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China); and other metal salt solutions purchased fromTianjin Fengchuan Chemical Reagent Technology Co., Ltd. (Tianjin, China). All reagents were used as received without further purification. The experimental water was ultrapure water (18.25 MΩ).