Renewable‐Resource‐Based Waste Materials for Supercapacitor Application

Abstract

Herein, renewable resource‐based waste materials (used tea leaves and molasses) were utilized as inexpensive and renewable carbon sources to develop Phosphorus and Nitrogen co‐doped Carbon (PNDC) materials for supercapacitor application. A prompt, low cost, single step, green and facile microwave assisted process was utilized to prepare PNDC materials using the aforementioned biomass. Concentration of the doping elements (P and N) was altered in the resulting PNDC materials by varying the mole ratio of used tea/molasses and ammonium polyphosphate (APP) in the reaction mixture. APP served as the Phosphorus and Nitrogen source as well as the microwave absorber. Detailed characterization of all four PNDCs ‐ two derived from molasses (MOLPNDCs) and two from used tea leaves (TEAPNDCs), were performed to investigate their supercapacitor performance. These materials were characterized both physically via BET, XPS, and SEM analysis and electrochemically via cyclic voltammetry, in both 1 M H2SO4 and 6 M KOH. Pore size, surface area, and elemental compositions of each PNDC was analyzed to investigate the critical parameter for supercapacitor performance of the materials. Among all PNDCs, MOLPNDC‐1 exhibited exceptionally high specific capacitance values of 160 Fg−1 in 6 M KOH electrolyte due to highly mesoporous structure and appropriate Nitrogen content. MOLPNDC‐1 was also found to be stable under continuous cycling for 1500 cycles in both acidic and alkaline conditions.

Characterization and Electrocatalytic Performance of Molasses Derived Co-Doped (P, N) and Tri-Doped (Si, P, N) Carbon for the ORR

“…PNDC and SiPNDC were prepared via a microwave-assisted technique reported elsewhere [27,37,38]. To prepare SiPNDC, a 2.0 g sample of molasses was blended well in a mortar and pestle with APP (1.2 g) and 0.6 g PDMS.…”

Phosphorus and nitrogen co-doped carbon derived from Cigarette Filter for adsorption of methylene blue dye from aqueous solution

“…Waste CFs were collected from receptacles located around UA Little Rock campus and carbonized through a facile, low-cost, microwave-assisted method described previously [22]. For DCCF synthesis, the CFs were weighed and combined with APP in a mass ratio of 1:0.4 g, and 2 drops of water was added to help initiate microwave carbonization process.…”

Metal-Free Carbon-Based Supercapacitors—A Comprehensive Review

“…The specific capacitance and surface area were found to be 161 F/g and 433 m 2 /g, respectively. We also used different precursors to produce doped nitrogen and phosphorous carbon using microwave technology to achieve materials with high specific capacitance values (182 F/g) [173,174]. It has been observed that microwave technique usually produces high surface area materials [167].…”