(523d) Synthesis of Nitrogen and Sulfur Co-Doped Graphene on Graphite Foam for Enhanced Electrochemical Oxygen Evolution and Phenol Degradation

Synthesis of Nitrogen and Sulfur Co-doped Graphene on Graphite
Foam for enhanced Electrochemical Oxygen Evolution and Phenol Degradation

¹Xiaomeng
Guo, ¹Xiaobin Fan, ¹Guoliang Zhang, ¹Fengbao
Zhang, ¹Yang Li, ¹Wenchao Peng*

¹School of Chemical Engineering and
Technology,
Tianjin University, Tianjin
300072, China,

wenchao.peng@tju.edu.cn

Fossil fuel
depletion and environmental pollution are two serious problems nowadays. Electrochemical
splitting of water to generate hydrogen fuel and oxygen gas is an important
process for clean energy generation. Electrocatalysis could also be used to
enhance the sulfate radical based advanced oxidation process for the
environment remediation.

Fig.
1 SEM image of GF (a), N,S co-doped GR/GF (b) and polarization curves obtained
with several catalysts as indicated (c); phenol removal under various
conditions (d)

In this study, we
synthesized N,S co-doped graphene on the surface of porous graphite foam (N,S
co-doped GR/GF) by an in situ method. Fig. 1a shows the typical SEM images for
GF with porous structure. Fig. 1b shows that the N,S co-doped GR was anchored
on the GF surface uniformly, and the structure of the GF was kept unchanged after
the doping process. The N,S co-doped GR/GF can be used
as a free-standing electrode directly for oxygen evolution reaction (OER) due
to the strong mechanical strength and 3D structure of GF. Electrochemical OER
activity of the electrodes was then investigated in 1 M KOH solution. In Fig. 1c,
S doped GR/GF, N doped GR/GF and N,S co-doped GR/GF show overpotential of 1.63,
1.62, and 1.56 V vs. RHE at a current density of 10 mA cm−2 (¦Ç₁₀). As
shown in Fig. 1d, the N,S co-doped GR/GF shows a good activity for PMS
activation after coated with N,S doped GR. The activity
for PMS activation could be enhanced further under CV conditions. The improved
electrochemical properties of doped GR and porous 3D structure of GF should be
important reasons for the activity enhancement. The N,S co-doped GR/GF is
therefore a promising free-standing electrode both for water splitting and pollutant
degradation.