In:
New Journal of Chemistry, Royal Society of Chemistry (RSC), Vol. 45, No. 34 ( 2021), p. 15544-15554
Abstract:
We report the synthesis of a nano-spinel cobalt decorated sulphur doped reduced graphene oxide (Co@S–rGO) composite exhibiting excellent electrocatalytic performance and electrochemical stability toward oxygen evolution reaction (OER) in an alkaline medium. Moreover, the so crafted noble metal free Co@S–rGO electrocatalyst, well characterized by UV-Vis spectroscopy, FTIR, XRD, SEM, and energy dispersive X-ray spectroscopy, exhibits promising activity toward electrochemical sensing of H 2 O 2 . For OER in an alkaline medium, the Co@S–rGO composite exhibits a Tafel slope of ca. 49 mV dec −1 , with an overpotential requirement of just 389 mV for a specific current density of 10 mA cm −2 . In the OER electrochemical stability tests, the Co@S–rGO electrocatalyst could maintain its peak OER performance for a time span of about 50 000 seconds during chronoamperometric measurements, while in the linear sweep voltammetry records almost negligible difference was observed between the final and the initial scan in a total of 1000 scans recorded over 25 hours for OER over Co@S–rGO. These chronoamperometric and voltammetric observations establish the excellent activity and long-term electrochemical stability of Co@S–rGO for OER in alkaline media. These current/potential and stability parameters observed for the OER performance of the Co@S–rGO composite are far better than that reported for various non-noble metal based state-of-the-art materials specifically crafted for OER. For the electrochemical sensing of H 2 O 2 , the Co@S–rGO composite exhibits a limit of detection as low as 23 nM with a sensitivity of 22743.85 μA M −1 cm −2 . The excellent OER performance and H 2 O 2 sensing activity of the Co@S–rGO composite can be attributed to the special synergism between the Co and S–rGO components and the extended electrochemically active surface area of Co nanodeposits in this noble metal free electrocatalyst.
Type of Medium:
Online Resource
ISSN:
1144-0546
,
1369-9261
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2021
detail.hit.zdb_id:
1472933-7
