Cetyltrimethylammonium bromide

Cobalt nitrate hexahydrate (Co(NO₃)₂·6H₂O), cetyltrimethylammonium bromide (CTAB), potassium hydroxide (KOH) and ferric chloride hexahydrate (FeCl₃·6H₂O) were provided by Tianjin Damao Chemical Reagent corporation. Tannic acid (TA) and sodium borohydride (NaBH₄) were purchased from Aladdin. Nafion solution (5 wt%) was purchased from the Aldrich corporation. All chemicals were used directly without further purification. In addition to the above, carbon paper was purchased from the Jinglong Special Carbon Company, Beijing, China.

Polycaprolactone diol (PCL diol) with an average molecular weight of 2000 g/mol and a hydroxyl value of 55.67 mg potassium hydroxide (KOH)/g was purchased from the Hunan Juren Chemical New Material Technology Co., Ltd. (Yueyang, China). Hexamethylene diisocyanate (HDI), toluene, and methanol were all purchased from Shanghai Macklin Biochemical Co., Ltd. (Shanghai, China). Bleached softwood kraft pulp, containing cellulose (92.1 wt%), hemicellulose (3.6 wt%), lignin (0.2 wt%), and a small amount of ash and moisture, was purchased from Shandong Daoxin New Materials Co., Ltd. (Weifang, China). Sodium-montmorillonite (MMT) with a cation exchange capacity of 90 mmol/100 g was purchased from Zhejiang Fenghong Clay Chemical Co., Ltd. (Huzhou, China). Sulfuric acid (98 wt%) and cetyltrimethylammonium bromide were purchased from Tianjin Damao Chemical Reagent Factory (Tianjin, China). PLA pellets (Ingeo^TM 4032D) with a melt flow index (MFI) of 7 g/10 min (210 °C, 2.16 kg) were purchased from Nature Works LLC (Minneapolis, MI, USA). PCL pellets (Capa^TM 6500) with an MFI of 5.9–7.9 g/10 min (160 °C, 2.16 kg) were purchased from Perstorp UK Ltd. (Malmö, Sweden).

Cetyl trimethyl ammonium bromide (CTAB), tetraethyl orthosilicate (TEOS), ethanol, dichloromethane, ammonia, sodium hydroxide, hydrochloride were obtained from Tianjin Damao Chemical Reagents. 3-aminopropyltriethyloxy silane (APTES), salicylaldehyde, furaldehyde and benzoaldehyde were obtained from Aladdin. And methyl eugenol (Macklin Co., Ltd.) was also used in this work. All chemicals were analytical grade and used as received without any further purification.