One Step Synthesis of Tertiary Co‐doped Graphene Electrocatalyst Using Microalgae Synechococcus elangatus for Applying in Microbial Fuel Cell

Abstract

In this work, heteroatom‐doped porous graphene was synthesized by pyrolysis method using microalgae Synechococcus elangatus as a biomass resource. The prepared samples were characterized by X‐ray diffraction (XRD), N2 sorption‐desorption, field emission scanning electron microscopy (FESEM) and X‐ray photoelectron spectroscopy (XPS). The electrochemical behavior of the synthesized samples was investigated for oxygen reduction reaction (ORR) and evaluated using microbial fuel cell (MFC). The results revealed that the catalytic activity of the prepared sample including N, S and P atoms on porous graphene (PG) was close to the Pt/C 20 wt.%. According to the linear sweep voltammetry (LSV) measurements, the onset potential of optimal sample (0.97 V versus RHE) was close to the Pt/C 20 wt.% (0.99 V versus RHE). Furthermore, the stability test demonstrated much better tolerance to the methanol crossover effects for the optimal sample in comparison to the Pt/C 20 wt.%. Moreover, the microbial fuel cell (MFC) test showed that the cell potential of the optimal sample is close to Pt/C 2 wt.%, and represented a high peak power density of 31.5 mW m−2, which is comparable to the Pt/C 20wt.% (38.6 mW m−2) cathodes, because of synergistic effect of N, S and P co‐doped carbon structure, which leads to improvement in catalytic activity.