Synthesis of Multiporous Carbons with Various Inorganic Template and Biochar via Solvent-Free Method for Supercapacitor and CDI Applications

Abstract

In this research solvent-free physical blending method was used to synthesize multiporous carbons A new carbon precursor Chinese Water Chestnut biochar (CWCB) was directly blended with inorganic template such as nano-sized CaCO3 and ZnO It was found that for CWCB precursor the appropriate pyrolysis duration at 900°C was 3 hours In addition the experiment results show that the pore size distribution of the as-prepared porous carbons depends on the dimension of the inorganic template As a result ZnO-templated porous carbon has higher content of mesoporous volume than that of the CaCO3-templated porous carbon Above all for CWCB multiporous carbons high specific surface area (up to 1537 m2 g-1) and tunable mesoporous volume can be achieved In addition to the synthesis of multiporous carbons the recycling of zinc ions from wasted solution has also been completed The synthesis of gelatin-ZnCO3 nanocomposite can be easily done by using biodegradable gelatin as organic template and a simple titration process with K2CO3/NaOH solution Different from the nano-sized ZnO the nanocomposite-templated multiporous carbons possess large meso and macropores Finally for supercapacitor application the as-prepared multiporous carbon electrodes all showed high specific capacitance (~130 F g-1) with good retention rate at 500 mV s-1 scan rate (~70%) and low ohmic resistance in LiClO4/PC electrolyte As to the CDI system the highest adsorption capacity of the multiporous carbon electrode was 11 01 mg g-1 Furthermore the adsorption capacity reached 10 11 mg g-1 within ten minutes suggest that multiporous carbons have fast electrosorption rate Key word: Multiporous carbon Recycling Supercapacitor CDI Green chemistry

Date of Award	2019
Original language	English
Supervisor	Hong-Ping Lin (Supervisor)