Spent coffee grounds derived P, N co-doped C as electrocatalyst for supercapacitor applications

• Published in: Electrochimica acta Vol. 168; pp. 414 - 422
• Main Authors: Ramasahayam, Sunil Kumar, Clark, Anna Lee, Hicks, Zachary, Viswanathan, Tito
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 20.06.2015
• Subjects: capacitance; co-doped; mesopores; microwave-assisted method; spent coffee grounds; mesopores; capacitance; co-doped; spent coffee grounds; microwave-assisted method
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2015.03.193

[Display omitted] •PNDCs have been synthesized by a novel microwave-assisted method.•PNDC-3 exhibits a high surface area of 999.64m2g−1.•PNDCs exhibit micropores, mesopores and macropores with high pore volume.•PNDC-3 exhibited a capacitance value as high as 286Fg−1 in 1 M H2SO4.•PNDC-2 was discovered to be electrochemically stable over continuous 2000 cycles. Spent coffee grounds, an abundant daily waste, were utilized to produce P, N co-doped C (PNDC) by a novel microwave-assisted method employing ammonium polyphosphate as the only other reactant. Different PNDCs (namely PNDC-1, PNDC-2 and PNDC-3) were synthesized by varying the ratio of spent coffee grounds to ammonium polyphosphate. The synthesized materials were found to contain spherically shaped particles as evidenced from scanning electron microscopy. X-ray photoelectron spectroscopy revealed PNDCs to contain P and N in addition to C and O. PNDC-3 was discovered to possess a surface area of 999.64m2g−1 with the presence of micropores, mesopores and macropores. PNDCs exhibited high specific capacitance values in acid and alkaline conditions with PNDC-3 exhibiting the highest specific capacitance value of 286Fg−1 in 1M H2SO4. Also, PNDC-2 was observed to be highly stable under acidic and alkaline conditions with continuous cycling.