Na2so4

SMX, tert-butyl alcohol (TBA) and fulvic acid were produced by Aladdin Reagent Company, China. Ferric sulfate and sodium bisulfite were obtained from Sinopharm Chemical Reagent Corporation Ltd., China. Methanol and isopropanol (IPA) were the products of Fisher corporation. H₂SO₄, NaOH, NaCl, NaNO₃, NaHCO₃, Na₂SO₄, Na₂S₂O₃, CuSO₄, Mg(NO₃)₂, Ca(NO₃)₂ were all of analytical grade and purchased from Chengdu Kelong Chemical Reagent Co., Ltd, China. Deionized water was used in all experiments.

The corn starch, tetracycline (TC, C₂₂H₂₄N₂O₈), ZnCl₂, NaCl, NaOH, and Humic Acid (HA) were obtained from Aladdin Reagent Co., Ltd (Shanghai, China). CaCl₂, NH₄Cl, and Na₂CO₃ were purchased from Bailingwei Technology Co., Ltd (Beijing, China). Na₂SO₄ and HCl were supplied by Kelong Chemical Reagent Co., Ltd (Chengdu, China). All chemicals are analytical grade, and deionized water was used for all experiments.

All chemicals were of analytical grade and used without further purification. Molybdenum powder (Mo, Tianjin Guangfu Technology Development Co. Ltd), hydrogen peroxide with 30 wt% (H₂O₂, Chengdu Kelong Chemical Reagent Factory), sodium sulfate (Na₂SO₄, Chengdu Kelong Chemical Reagent Factory), lithium chloride (LiCl, Chengdu Kelong Chemical Reagent Factory), polyvinyl alcohol (PVA1788, 99.0%, Sigma-Aldrich), PEDOT:PSS and polyethylene terephthalate (PET) substrates were used for electrode fabrication and electrochemical characterization. PEDOT:PSS (1.3–1.7 wt%) was purchased from Cool Chemical Tech Co., China. The high purity silver target (99.99%) was purchased from Sino Connaught New Material Tech Co., China.