Chun-Hao ChiangChun-Hung YuYang-Sheng LuYueh-Chiang YangYin-Cheng LinHsin-An ChenSheng-Zhu HoYi-Chun ChenAkichika KumataniChen ChangPai-Chia KuoJessie ShiueShao-Sian LiPo-Wen ChiuCHUN-WEI CHEN2024-09-302024-09-302024-08-2615306984https://www.scopus.com/record/display.uri?eid=2-s2.0-85202457243&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/721619Ferroelectric catalysts are known for altering surface catalytic activities by changing the direction of their electric polarizations. This study demonstrates polarization-switchable electrochemistry using layered bismuth oxyselenide (L-Bi2O2Se) bifunctional microreactors through ferroelectric modulation. A selective-area ionic liquid gating is developed with precise control over the spatial distribution of the dipole orientation of L-Bi2O2Se. On-chip microreactors with upward polarization favor the oxygen evolution reaction, whereas those with downward polarization prefer the hydrogen evolution reaction. The microscopic origin behind polarization-switchable electrochemistry primarily stems from enhanced surface adsorption and reduced energy barriers for reactions, as examined by nanoscale scanning electrochemical cell microscopy. Integrating a pair of L-Bi2O2Se microreactors consisting of upward or downward polarizations demonstrates overall water splitting in a full-cell configuration based on a bifunctional catalyst. The ability to modulate surface polarizations on a single catalyst via ferroelectric polarization switching offers a pathway for designing catalysts for water splitting.true2D materialsferroelectric polarizationmicroreactorsswitchable electrochemistrywater splittingjournal article10.1021/acs.nanolett.4c031282-s2.0-85202457243