posted on 2020-05-05, 09:25authored bySiyu Sheng, Bairu Shi, Cheng Wang, Liang Luo, Xiao Lin, Pengsong Li, Fanhong Chen, Zhicheng Shang, Hong Meng, Yun Kuang, Wen-Feng LinWen-Feng Lin, Xiaoming Sun
The bubbles electrochemically generated by gas evolution reactions
are commonly driven off the electrode by buoyancy, a weak force used to overcome
bubble adhesion barriers, leading to low gas transporting efficiency. Herein, a Janus
electrode with asymmetric wettability has been prepared by modifying two sides of a
porous stainless-steel mesh electrode, with superhydrophobic polytetrafluoroethylene
(PTFE) and Pt/C (or Ir/C) catalyst with well-balanced hydrophobicity, respectively;
affording unidirectional transportation of as-formed gaseous hydrogen and oxygen
from the catalyst side to the gas-collecting side during water splitting. “Bubble-free”
electrolysis was realized when “floating” the Janus electrode on the electrolyte.
Anti-buoyancy through-mesh bubble transportation was observed when immersing
the electrode with PTFE side downward. The wettability gradient within the electrode
endowed sticky states of bubbles on the catalyst side, resulting in efficient
“bubble-free” gas transportation with 15 folds higher current density than submerged
states.
Funding
National Natural Science Foundation of China (NSFC)
National Key Research and Development Project (No. 2018YFB1502401, 2018YFA0702002)
Royal Society and the Newton Fund through the Newton Advanced Fellowship award (NAF\R1\191294)
Program for Changjiang Scholars and Innovation Research Team in the University (No. IRT1205)
History
School
Aeronautical, Automotive, Chemical and Materials Engineering