Here, we demonstrate a two-step electrochemical approach for the synthesis of cobalt chalcogenides, CoQ (Q = S or Se) based on the prior modification of a substrate with S or Se, followed by electrochemical reduction in a Co 2+ -complexing electrolyte to afford CoS or CoSe in film form. The two-step strategy circumvents a common problem with the electrodeposition of metal chalcogenides, namely admixture of the target material with undesired phases such as excess metal or the chalcogen. The strategy was combined with complexation to shift the free metal deposition regime to more negative potentials. Compositional analysis showed that as-synthesized films retain a stoichiometric ratio of Co and S or Se and XPS analysis confirmed the formation of CoS and CoSe. The electrodeposited films were successfully used as electrocatalysts for the triiodide/iodide redox system and showed comparable (or even, superior) performance to a Pt electrode. As also demonstrated both by the pr...

中文翻译：

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化学计量钴硫属化物薄膜的阴极电沉积

在这里，我们展示了基于先用S或Se修饰底物，然后在Co 2+复合电解质中进行电化学还原的两步电化学方法，用于合成钴硫属元素化物CoQ（Q = S或Se）以薄膜形式提供CoS或CoSe。两步策略解决了金属硫属元素化物电沉积的一个常见问题，即目标材料与不想要的相（例如过量金属或硫属元素化物）的混合。该策略与络合相结合，将自由金属沉积机制转移到更多的负电势上。成分分析表明，合成后的薄膜保留了Co和S或Se的化学计量比，而XPS分析证实了CoS和CoSe的形成。电沉积膜成功地用作三碘化物/碘化物氧化还原体系的电催化剂，并显示出与Pt电极相当的性能（甚至更好）。事实也证明了...