am3c09901_si_001.avi (83.12 kB)
Open-Microcolumn Array: A Novel Approach for Enhanced Electrocatalytic Bubble Desorption in Microreactors
mediaposted on 2023-09-28, 20:43 authored by Yibing Ma, Yaya Zhou, Yaqing Xie, Ningxuan Jin, Yushuang Cui, Yiqiang Qin, Haixiong Ge
High-efficiency electrocatalytic water splitting requires high intrinsic activity of catalysts and even more importantly favorable mass transfer. However, gas bubbles adhering to the surface of catalysts limit the re-expose of catalytic active sites to the electrolyte and reduce the catalytic activities. The efficient desorption of bubbles can be facilitated by a hierarchical multiscale structure of the electrode surface. Herein, we report an opened periodic three-dimensional electrode composed of iron (Fe)-cobalt (Co)-nickel (Ni) (oxy)hydroxide nanorods (NRs) grown in situ on a high aspect ratio nickel microcolumn array (NCA) for electrocatalytic water splitting. Compared with the flat nickel plate, the NCA not only increases the surface area for catalyst loading but also improves the wettability of the electrolyte on the electrode surface, exhibiting superhydrophilicity/superaerophobicity (the electrolyte and the bubble contact angles were about ∼0 and 163°, respectively), which accelerates the bubble evolution and desorption process. The X-ray photoelectron spectroscopy indicates that the synergy of Fe–Co–Ni could enhance the ratio of Co3+/Co2+ and Ni3+/Ni2+ and promote the electrocatalytic activity. Benefiting from the microstructure design and synergistic effects, the Co4Fe0.5Ni0.5OOH-NR@NCA electrode achieves a superior OER performance with an overpotential of 199 mV at 10 mA·cm–2.
superior oer performanceopened periodic threehierarchical multiscale structureflat nickel platedimensional electrode composedelectrocatalytic water splittingcatalytic active sitesbubble contact angles5 sub4 subgas bubbles adheringfe )- cobaltco )- nickel2 + supnca electrode achieveselectrocatalytic activitycatalytic activitiesbubble evolutionelectrode surface· cmsynergistic effectsnovel approachmicrostructure designmicroreactors highmicrocolumn arrayexhibiting superhydrophilicityefficient desorptiondesorption processcatalyst loadingalso improves199 mv