Copper nitrate

Raw prawn shell (Penaeus vannamei) was provided by Zhoushan Evergreen Seafood Food Co., Ltd., Zhoushan, Zhejiang, China. It was washed repeatedly with deionized water to remove various impurities, and dried at 110 °C. A metal ion Cd²⁺ solution was prepared by using cadmium nitrate, which was purchased from China Traditional Chinese Medicine Group Chemical Reagents Co., Ltd. (Shanghai, China). Cadmium stock solution (Cd²⁺ mass concentration of 0.1 g/L) was prepared by dissolving 0.2744 g of cadmium nitrate in 1 L deionized water.
All work solutions were obtained by proper dilution with deionized water. Hydrochloric acid, sulfuric acid, phosphoric acid, potassium hydroxide, copper nitrate, potassium dichromate, and other chemicals used in this study were all of analytical reagent grade and purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). Deionized water was used throughout the experimental process.

Nickel nitrate [Ni(NO₃)₂ 
· 6H₂O], copper nitrate [Cu(NO₃)₂ 
· 3H₂O] were purchased from Sinopharm Chemical Reagent Co., Ltd. Sodium hydroxide, urea, ethanediamine (EDA, 99 wt%), and hydrazine (80 wt%) were purchased from Aladdin Reagent Co., Ltd., and deionized water was employed for the preparation of all solutions. GO was synthesized by the modified Hummers method4^{47 (link)}, and then dispersed in deionized water by ultrasonication bath for 4 h at 25 °C to afford a uniform suspension with a concentration of 0.5 mg/mL.

Poplar leaves were collected in the campus of Shandong First Medical University and Shandong Academy of Medical Sciences. Potassium bicarbonate, hydrochloric acid, sulphuric acid, sodium hydroxide, sodium chloride, potassium carbonate, calcium chloride, magnesium sulfate, copper nitrate, and iron nitrate were purchased from Sinopharm Chemical Reagent Co., Ltd. (Beijing, China). Nitrogen was purchased from Taian Yingchun Gas Co., Ltd. (Taian, China). Oxytetracycline hydrochloride was purchased from Beijing InnoChem Science and Technology Co., Ltd. (Beijing, China). All purchased reagents were used without further purification.

Cellulose nanocrystal (CNC) was provided by Tianjin Woodelfbio Cellulose Co., Ltd., Tianjin, China. Sodium periodate and DETA were purchased from Sigma-Aldrich Co. Ltd. Copper nitrate, Cu(NO₃)₂, lead nitrate, Pb(NO₃)₂, and potassium bichromate, K₂Cr₂O₇, were purchased from Sinopharm Chemical Reagent Co. Ltd., China.

Sodium silicate, manganese nitrate, zinc nitrate, copper nitrate, cerium nitrate, and bismuth nitrate were of analytical grade and purchased from Sinopharm Chemical Reagent Co., Ltd. Soluble starch (Shanghai, China). Nessle’s reagent, potassium dichromate, silver sulfate, and mercury sulfate were of analytical grade and purchased from Nanjing Chemical Reagent Co., Ltd. (Nanjing, China) Palygorskite was 400 mesh, purchased from Changzhou Dingbang Mineral Products Co., Ltd. (Changzhou, China) Coal chemical wastewater was taken from a coal chemical enterprise in Yunnan and used in the experiment. The water sample was gray-brown, dark in color, and turbid. The water quality was shown in Table 1.

Bovine serum albumin (BSA) was purchased from Shanghai Shisheng Sibas Advanced Technology Co., Ltd. (Shanghai, China). Copper nitrate (AR, 99.0%–102.0%), thioacetamide (AR, 99.0%), and nitric acid (AR, 65.0%–68%) were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). Ultrapure water (18.2 MΩ) used in all experiments was prepared with Milli-Q^TMDirect (Merck China, Shanghai, China).
Six-week-old male Kunming mice (18–22 g) were purchased from Qingdao Daren Fucheng Animal Husbandry Co., LTD. H22 hepatocellular carcinoma ascites tumor mice were purchased from the Institute of Materia Medica, Shandong Academy of Medical Sciences. All animals were maintained in a standard environment with 12 h light/dark cycle, temperature (22–24°C), and humidity (40–60%). Mice had free access to standard mouse chow and water. All the animal experiments were approved by Animal Care and Use Committee of Qingdao University and carried out under the institution guidelines for ethical animal use.

Graphene oxide (layer < 3, purity 99%) was purchased from J&K Scientific LTD (Shanghai, China). Bentonite was taken from Chunyuan Company (Jinzhou, China) and chemical composition of bentonite was shown in Table 1. Ferric chloride tetrahydrate, sodium borohydride, anhydrous ethanol, sodium hydroxide and copper nitrate were purchased from Sinopharm Chemical Reagent Co., Ltd (Beijing, China) (analytical purity).