(569bc) Fabrication of Catalytic Condensers with High-? Dielectric Materials for Programmable Catalysis

Manipulation of electron density on the catalytic active sites is of topical interest to control catalytic reactions toward more desired ways with activity and selectivity. To this end, it is vitally important to develop catalytic condensers that can accumulate electrons or holes with substantially high density on the catalytic surface. Here, high-κ dielectric metal oxides were used as a dielectric layer for Pt-on-carbon catalytic condensers. The dielectric layers were deposited with 50 ~ 150 nm thickness via the conventional radio frequency (RF) magnetron sputtering technique. On top of the dielectric layer, a 1 nm-thick carbon layer was deposited by sputtering followed by the deposition of a 1 nm Pt layer through e-beam evaporation. Throughout the device fabrication process, the most important step for the device's dielectric performance was the dielectric layer deposition. The dielectric layer sputtering process has been extensively optimized with various metal oxide targets by varying the deposition conditions such as RF gun power, Ar: O₂ stoichiometry for the plasma, and substrate temperature. Additionally, post-annealing was performed after the deposition of the dielectric layer in order to give crystallinity or heal the oxygen vacancies in the dielectric layer. The optimized catalytic condensers exhibited higher charge accumulation compared to that of catalytic condensers developed in previous works.