Sulfonation of graphene nanosheet-supported platinum via a simple thermal-treatment toward its oxygen reduction activity in acid medium

The sulfonated graphene nanosheet-supported platinum (s-Pt/GNS) catalyst synthesized via a simple thermal-treatment in the presence of concentrated sulfuric acid was reported in this study. Influence of sulfonation on its structural, surface, morphological and catalytic characteristics of as-prepared s-Pt/GNS was explored using X-ray diffractometer, Raman spectrometry, zeta potential analyzer, scanning and transmission electron microscopes, and cyclic voltammetry. For the oxygen reduction reaction, the current density generated from the s-Pt/GNS at 0.6 V was approximately 32.5 A g−1 Pt, which was about 193% higher than that of original Pt/GNS.

Graphical abstractSulfonated graphene nanosheets-supported platinum delivers about five times greater Pt mass-normalized current density at 0.6 V than that of 40 wt. % Pt/C in an oxygen reduction reaction test, which is ascribed to sulfonic groups grafted onto the GNS surface were able to minimize the triple-phase boundaries efficiently.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Sulfonation of Pt/GNS is successfully prepared by the simple thermal-treatment. ► Influence of sulfonation on its structure and ORR activity of Pt/GNS is explored. ► The ORR activity of s-Pt/GNS is about 193% higher than that of original Pt/GNS.