Valorization of coffee bean waste: a coffee bean waste derived multifunctional catalyst for photocatalytic hydrogen production and electrocatalytic oxygen reduction reactions. Issue 85 (30th August 2016)

• Record Type: Journal Article
• Authors: Unni, Sreekuttan M.; George, Leena; Bhange, Siddheshwar N.; Devi, R. Nandini; Kurungot, Sreekumar
• Is Part Of: RSC advances. Volume 6:Issue 85(2016)
• Page Start: 82103
• Page End: 82111
• Publication Date: 2016-08-30
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra14907c
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : The valorization of coffee bean waste (CBW) by producing nitrogen doped porous carbon with photocatalytic and electrocatalytic properties using a silica templating method. Abstract : Here, we report the valorization of coffee bean waste (CBW) by producing nitrogen doped porous carbon (p-Cof) having both photocatalytic and electrocatalytic properties using a silica templating method. Morphological investigation of p-Cof reveals the presence of assemblies of highly porous flat carbon blocks. p-Cof exhibits a high surface area (1213 m 2 g −1 ) and a wide range of micro- and mesopores with good electrical conductivity. Along with this, the surface of p-Cof displays the presence of graphitic and pyridone-type nitrogen coordinations, which help p-Cof to perform as a multifunctional catalyst as revealed from its catalytic activities towards photocatalytic hydrogen production (PHP) and electrocatalytic oxygen reduction reactions. p-Cof produces 334 μmol h −1 g −1 of hydrogen from water under visible light and 575 μmol h −1 g −1 of hydrogen under solar light irradiation with excellent stability. Along with this, p-Cof also displays improved oxygen reduction reaction (ORR) activity in alkaline medium. A better onset potential (0.91 V vs. RHE) and half-wave potential (0.75 V vs. RHE) are displayed by p-Cof compared to the catalyst derived from the simple annealing of CBW without employing the silica template. Along with the better electrochemical activity, p-Cof shows excellent ORR kinetics and electrochemical stability compared to the current state-of-the-art Pt/C.