2 2 6 6 tetramethylpiperidine

Piperidine, DBU, trifluoroacetic acid and acetonitrile (ACN) were purchased from Energy Chemical Technology (Shanghai) Co., Ltd. 2,4,6-Trimethyl-1,3,5-triazine (TMT), 2,4,6-trimethylpyridine-3,5-dicarbonitrile (DCTP), 2,4,6-tris(4-formylphenyl)-1,3,5-triazine (TFPT), 1,3,5-tris(4-formylphenyl)benzene (TFPB), 4-[4-[3,5-bis[4-(4-formylphenyl)phenyl]phenyl]phenyl]benzoic acid (DAFB), 4,4,4-(benzene-1,3,5-triyltris(ethyne-2,1-diyl))tribenzaldehyde (BTTA), 4,4’-biphenyldicarboxaldehyde (BDA), 4,4”-p-terphenyldicarboxaldehyde (TDA), 4-[2-(4-formylphenyl)ethynyl]benzaldehyde (EDA), tris(4-formylphenyl)amine (TPA), and p-phenylenediamine (Pa) were purchased from Jilin Chinese Academy of Sciences-Yanshen Technology Co., Ltd. Tetrahydrofuran (THF), 1,4-dioxane, mesitylene, benzaldehyde, NaOH, KOH, EtONa, N,N-dimethylformamide (DMF), 2,2,6,6-tetramethylPiperidine (TEMP), ethanol, methanol, CH₂Cl₂, acetone, and n-BuOH were purchased from Sinopharm Chemical Reagent Co., Ltd. Ultrapure water was prepared from the Millipore system (18.25 MΩ-cm). All the electrochemical measurement used phosphate buffered (PBS, pH = 7.5) containing mixture solutions of 0.1 M KCl, 0.1 M K₂HPO₄, and 0.1 M KH₂PO₄ as the electrolyte.

The waste bamboo paper was collected from the laboratory. Montmorillonite (MMT) was bought from Zhejiang Fenghong New Materials co., Ltd. (Huzhou, China). Methylene blue (MB), copper sulfate pentahydrate, and 2,2,6,6-Tetramethylpiperidine (TEMPO) were obtained from Sinopharm Chemical Regent Co., Ltd. (Shanghai, China). Polyethyleneimine (PEI, 50% aqueous solution) was purchased from Aladdin Reagent Co., Ltd. (Shanghai, China). Sodium hypochlorite (NaClO), glacial acetic acid (CH₃COOH), sodium bromide (NaBr), sodium hydroxide (NaOH), and hydrochloric acid (HCl) were obtained from Chengdu Kelong Chemical Co., Ltd. (Chengdu, China). All chemicals were of analytical grade and used without further purification.