We investigated the effect of O₃ oxidation treatment on the electrochemical CO₂ reduction activity of a Ag cathode. The surface structure of the Ag electrode was altered using a AgO precursor, which allowed for effective and selective CO₂ reduction with high current density. The total current density and faradaic efficiency to CO evolution of the Ag electrode treated using O₃ (rO₃_Ag electrode) were 4.0 mA cm^–2 and 96%, respectively, at an applied voltage of −1.6 V vs Ag/AgCl, whereas those of an untreated Ag foil electrode were 1.3 mA cm^–2 and 62%, respectively. Despite enlargement of the electrochemical surface area of the active Ag species by O₃ treatment, the turnover frequency of CO evolution using the rO₃_Ag electrode was twofold greater than that obtained using the untreated Ag foil electrode. Grazing-incidence X-ray diffraction revealed that the Ag particles grew anisotropically along the [111] direction on the electrode surface due to the reduction of AgO species, which were formed during O₃ treatment; this result indicated that the obtained Ag surface was favorable for the electrochemical reduction of CO₂ while suppressing H₂ production. This simple surface reforming technique enhanced the activity for the electrochemical reduction of CO₂ to CO and could be applied in the design of future electrodes for recycling CO₂ into feedstocks.

中文翻译：

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O ₃处理表面重整对Ag阴极电化学CO ₂还原活性的影响

我们研究了O ₃氧化处理对Ag阴极电化学CO ₂还原活性的影响。使用AgO前驱体可以改变Ag电极的表面结构，从而可以在高电流密度下有效，选择性地还原CO ₂。在-1.6 V施加电压对Ag / AgCl的条件下，使用O ₃（rO ₃ _Ag电极）处理的Ag电极的总电流密度和对CO演化的法拉第效率分别为4.0 mA cm ^–2和96％。未经处理的银箔电极的电导率分别为1.3 mA cm ^–2和62％。尽管O增加了活性Ag物质的电化学表面积_在图3的处理中，使用rO ₃ _Ag电极的CO释放的周转频率比使用未处理的Ag箔电极获得的CO的周转频率大两倍。掠入射X射线衍射表明，由于在O ₃处理过程中形成的AgO种类减少，Ag颗粒在电极表面沿[111]方向各向异性生长。该结果表明，获得的Ag表面在抑制H ₂产生的同时有利于CO ₂的电化学还原。这种简单的表面重整技术增强了将CO ₂电化学还原为CO的活性，可用于未来回收CO的电极的设计中₂成原料。