Affiliation:
1. Key Laboratory of Bio‐Inspired Smart Interfacial Science and Technology School of Chemistry Beihang University Beijing 100191 P. R. China
2. School of Mathematics and Physics University of Science & Technology Beijing Beijing 100083 P. R. China
3. Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100191 P. R. China
Abstract
AbstractOverall water splitting is a promising technology for sustainable hydrogen production, but the primary challenge is removing bubbles from the electrode surface quickly to increase hydrogen production. Inspired by the directional fluid transport properties of natural biological surfaces like Nepenthes peristome and Morpho butterfly's wings, here a strategy is demonstrated to achieve highly efficient overall water splitting by a bubble‐guidance electrode, that is, an anisotropic groove‐micro/nanostructured porous electrode (GMPE). Gradient groove micro/nanostructures on the GMPE serve as high‐speed bubble transmission channels and exhibit superior bubble‐guidance capabilities. The synergistic effect of the asymmetric Laplace pressure generated between microscale porous structure and groove patterns and the buoyancy along the groove patterns pushes the produced bubbles directionally to spread, transport, and detach from the electrode surface in time. Moreover, the low adhesive nanosheet arrays are beneficial to reduce bubble size and increase bubble release frequency, which cooperatively improve mass transfer with the microscale structure. Notably, GMPE outperforms planar‐micro/nanostructured porous electrode (PMPE) in hydrogen/oxygen evolution reactions, with GMPE||GMPE showing better water splitting performance than commercially available RuO2||20 wt.% Pt/C. This work improves electrodes for better mass transfer and kinetics in electrochemical reactions at solid‐liquid‐gas interfaces, offering insight for designing and preparing gas‐involved photoelectrochemical electrodes.
Funder
National Natural Science Foundation of China
Fundamental Research Funds for the Central Universities