Polysulfide functionalized reduced graphene oxide for electrocatalytic hydrogen evolution reaction and supercapacitor applications

• Published in: International journal of hydrogen energy 2023-05, Vol.48 (45), p.17014-17025
• Main Authors: Kapuria, Arijit, Mondal, Tapas Kumar, Shaw, Bikash Kumar, Su, Yan-Kuin, Saha, Shyamal K.
• Format: Article
• Language: English
• Subjects: Hydrogen evolution reaction; Polysulfide; Reduced graphene oxide; Supercapacitor
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2023.01.214

Functionalized carbon based 2D materials are promising candidates for low cost and environment friendly electrocatalyst for hydrogen evolution reaction (HER) and supercapacitor applications. To overcome the limitations posed by the noble metals and transition metal based composites, we have successfully synthesized metal free polysulfide functionalized reduced graphene oxide (GPS) in a simple chemical route. Structure and morphology of the material are characterized via XRD, FTIR, Raman, TEM, XPS measurements. The material behaves as an efficient HER electrocatalyst in acidic medium as well as energy storage device. It shows an onset potential of 97 mV and overpotential of 254 mV to reach a high current density of 10 mA/cm2. DFT calculations are carried out to understand the structural stability and identification of active sites of the material. Boosting catalytic activity via increasing the number of active sites is an elegant approach. In this material we have used the S atoms of polysulfide polymer to facilitate hydrogen adsorption and desorption, thus improving the hydrogen evolution ability. The supecapacitor attains the high specific capacitance 347 F/g at the current density of 1 A/g. The origin of such performances is due to synergistic effect of both the graphene network and the polysulfide functionalizations. [Display omitted] •The reduced graphene oxide – polysulfide (GPS) composite has been fabricated via simple condensation strategy.•The electron cloud delocalisation between sulfur atoms create fast electron transfer pathway for HER & supercapacitor.•The polysulfide functionalization creates active sites and effectively improves the catalytic and charge storage properties.•An inexpensive carbon based metal-free catalyst and energy storage device is introduced.