Bionic Janus microfluidic hydrogen production with high gas–liquid separation efficiency

Water electrolysis offers the advantages of emission-free and highly efficient energy conversion in terms of sustainable energy development and environmental pollution. However, water electrolysis is strongly affected by the detachment of bubbles from the electrodes commonly enabled by buoyancy, thereby reducing the performance of the electrolytic cells in harsh environments like in space. Herein, a bionic Janus microchannels with active gas–liquid separation for water electrolysis is proposed. There is a Janus membrane with superaerophilic top surface and inner micropores over the microchannels, and such a unique type of microchannels can capture and unidirectionally manipulate the hydrogen (H2) bubbles generated on the surface of the electrode during the water electrolysis reaction at high speed with long-term stability. It is worth noting that the gas–liquid separation through the Janus membrane does not hinder the flow of electrolyte in the microchannel due to its hydrophilic inside surfaces, which can maintain the great stability of the electrolysis. Moreover, mimicked leaves and trees for water catalysis are further demonstrated with ultrahigh electrolysis efficiency based on the active detachment of H2 bubbles enabled by Janus micropores. The present bionic Janus microchannels for high-efficient water electrolysis to produce H2 is intended to provide a new power supply solution for human space living and exploration.