Hydrazine hydrate

GO flakes were obtained from XianFeng NANO Co., Ltd. Pyranine (i.e. Trisodium 8-hydroxypyrene-1,3,6-trisulphonate, >85%) and hydrazine hydrate (>98%) were purchased from Alfa Aesar. Ammonium hydroxide (28% NH₃ in H₂O), lithium chloride (≥99%), magnesium chloride (99.99%), magnesium nitrate (≥99%), sodium chloride (≥99%), potassium nitrate (≥99%), and potassium chloride (≥99%) were all purchased from Sigma-Aldrich. All the chemicals were analytical grade and used as received without further purifications.

Pyrene and γ-benzyl-l-glutamic acid ester were used as received from Acros. Palladium on carbon (Pd/C, 10 wt%), 4-fluoronitrobenzene, hydrazine hydrate (98%), triphosgene, and potassium carbonate were obtained from Alfa Aesar. Glacial acetic acid was purchased from Fluka. Ethanol (EtOH), dimethylsulfoxide (DMSO), methanol (MeOH), THF, and acetonitrile were obtained from Merck and distilled over CaH₂ prior to use. MWCNTs [diameters (main range): 40–60 nm; lengths: 5–15 μm] were ordered from Centron Biochemistry Technology (Taiwan). MWCNTs were purified through sonication in toluene for 1 h, ultrafiltration, and drying under vacuum overnight. BLG-NCA^{45 (link)} and 1-aminoPyrene^{46 (link)} were synthesized using previously reported methods.

Reagents and solvents were obtained from commercial sources and used as received. Carbazole (95%), acetic anhydride (99%), copper (II) nitrate trihydrate (98%), and acetic acid (99.8%) were obtained from Sigma-Aldrich. Dimethoxymethane (95%) and palladium on activated carbon, 10% Pd/C, were purchased from Acros. 1-Fluoro-4-nitrobenzene (99%), potassium carbonate (99%), potassium hydroxide (KOH, 90%), trifluoromethanesulfonic acid (F₃CSO₃H, 98%), and hydrazine hydrate (98%) were ordered from Alfa Aesar. Methanol (99.8%), acetone (99.5%), ethylacetate (EA, 99.8%), petroleum ether (≥90%), tetrahydrofuran (THF, 99.9%), ethanol (99.8%), and dichloromethane (DCM, 99.8%) were obtained from Showa (Tokyo, Japan).

The following reagents were purchased from the listed vendors and used as received: 2,3,4,5,6-pentafluorobenzyl bromide and 18-crown-6 (SynQuest Laboratories, Alachua, FL, USA); 4-aminophenol, 4,4′-bicyclohexanol (mixture of isomers), 4,4′-(hexafluoroisopropylidene)-diphthalic anhydride (6FDA), 2,2′-bis(4-aminophenyl)hexafluoropropane, and 2,2′-bis(trifluoromethyl)benzidine (TCI America, Portland, OR, USA); acetone (Fisher Scientific, Atlanta, GA, USA); hydrazine hydrate (Alfa Aesar, Atlanta, GA, USA); 2-chloro-5-nitrobenzotrifluoride and sodium hydride (Sigma-Aldrich, St. Louis, MO, USA), LC-MS grade acetonitrile, water, and formic acid were procured from Fisher Scientific. Magnesium sulfate, potassium carbonate, potassium chloride, silica gel, resorcinol, acetonitrile, chloroform, deionized water, N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), dimethyl sulfoxide, ethanol, ethyl acetate, hexane, N-methyl pyrrolidone (NMP), trichlorofluoromethane, and 5% Pd/C were taken from laboratory stock.

Sodium tellurite (Na₂TeO₃, 99%) and acetone (ACS reagent, 99.5%) were obtained from Sigma Aldrich (Incheon, Korea). Ammonia solution (35%, extra pure), hydrazine hydrate (80%, wt/wt%), and polyvinylpyrrolidone (PVP, MW 58,000) were purchased from Alfa Aesar (Seoul, Korea). For the 2D Te synthesis, Na₂TeO₃ (0.00045 mol, 0.1 g) and PVP (1 g) were dissolved in deionized water (DI), with continuous stirring to form a transparent solution. The solution was transferred to a 100-mL Teflon lined stainless steel autoclave and Ammonia solution and hydrazine hydrate were added at a 2:1 volume ratio. The autoclave was tightly sealed and placed in a reaction oven at 180 °C for 40 h. After the reaction, the transparent solution changed to a silver-grey color. For the thinning process (chemical exfoliation), acetone and crude colloid were mixed in a 3:1 volume ratio and allowed to stand for 4 h. After the reaction, exfoliated 2D Te was centrifuged at 5000× g for 5 min. The supernatant was discarded and the precipitate was redispersed in DI water. This process was repeated several times to remove unreacted chemicals. The 2D Te colloid was diluted to obtain a proper sample density.