Sodium nitrate nano3

Purified natural graphite powder with an average particle size less than 48 μm was purchased from Nanjing XFNANO Materials Tech Co., Ltd (Nanjing, China). Ninety-eight percent sulfuric acid (H₂SO₄), 38% hydrochloric acid (HCl), 30% hydrogen peroxide (H₂O₂), absolute ethanol (C₂H₅OH), and sodium nitrate (NaNO₃) were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China) Potassium permanganate (KMnO₄), tetrabutyl titanate (C₁₆H₃₆O₄Ti), P25 (anatase, hydrophilic, and lipophilic grades), and N-Methyl pyrrolidone (C₅H₉NO) were purchased from Aladdin (Shanghai, China). All chemicals were analytically pure reagents, and the water used in the experiments was deionized water. For the sake of brevity, TBT denotes tetrabutyl titanate and NMP denotes N-Methyl pyrrolidone.

All reagents were not purified further before use. Methylbenzene, hydrochloric acid (HCl), lysine (Lys), arginine (Arg), titanium tetrachloride (TiCl₄), tetrabutyltitanate, gold (III) chloride (HAuCl₄·3H₂O), leucine (Leu), cysteine (Cys), proline (Pro), glycine (Gly), barium hydroxide octahydrate (Ba(OH)₂·8H₂O), formic acid, ethylene diamine tetraacetic disodium (EDTA−2Na), chloroplatinic acid (H₂PtCl₆), 3,3′,5,5′−tetramethylbenzidine (TMB, ≥99%), L−histidine (L−His), glutathione (GSH), glutamic acid (Glu), and fetal bovine serum were purchased from Macklin Biochemical Co., Ltd. (Shanghai, China). Sodium borohydride (NaBH₄), disodium hydrogen phosphate (Na₂HPO₄), p−Benzoquinone (p−BQ), isopropanol (IPA), potassium nitrate (KNO₃), citric acid, ascorbic acid (AA), and sodium nitrate (NaNO₃) were purchased from Sinopharm Chemical Reagents Co., Ltd. (Shanghai, China).