In view of developing photoelectrosynthetic cells which are able to store solar energy in chemical bonds, water splitting is usually the reaction of choice when targeting hydrogen production. However, alternative approaches can be considered, aimed at substituting the anodic reaction of water oxidation with more commercially capitalizable oxidations. Among them, the production of bromine from bromide ions was investigated long back in the 1980s by Texas Instruments. Herein we present optimized perylene-diimide (PDI)-sensitized antimony-doped tin oxide (ATO) photoanodes enabling the photoinduced HBr splitting with >4 mA/cm² photocurrent densities under 0.1 W/cm² AM1.5G illumination and 91 ± 3% faradaic efficiencies for bromine production. These remarkable results, among the best currently reported for the photoelectrochemical Br^– oxidation by dye sensitized photoanodes, are strongly related to the occupancy extent of ATO’s intragap (IG) states, generated upon Sb-doping, as demonstrated by comparing their performances with PDI-sensitized analogues on both undoped SnO₂- and TiO₂-passivated ATO scaffolds by means of (spectro)electrochemistry and electrochemical impedance spectroscopy. The architecture of the ATO–PDI photoanodic assembly was further modified via the introduction of a molecular iridium-based water oxidation catalyst, thus proving the versatility of the proposed hybrid interfaces as photoanodic platforms for photoinduced oxidations in PEC devices.

中文翻译：

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内带隙态在用于太阳能燃料生产的敏化锑掺杂氧化锡光阳极中的作用


鉴于开发能够以化学键储存太阳能的光电合成电池，水分解通常是目标制氢时的首选反应。然而，可以考虑替代方法，旨在用更具商业价值的氧化代替水氧化的阳极反应。其中，德州仪器 (Texas Instruments) 早在 20 世纪 80 年代就开始研究利用溴离子生产溴。在此，我们提出了优化的苝二酰亚胺 (PDI) 敏化锑掺杂氧化锡 (ATO) 光阳极，能够在 0.1 W/cm ² 光电流密度的光诱导 HBr 分裂。 /b1> AM1.5G 照明和 91 ± 3% 的溴生产法拉第效率。这些显着的结果是目前报道的染料敏化光电阳极光电化学 Br ^– 氧化的最佳结果之一，与 Sb 掺杂时产生的 ATO 内间隙 (IG) 态的占据程度密切相关，如通过（光谱）电化学和电化学阻抗谱将它们与 PDI 敏化类似物在未掺杂的 SnO ₂ - 和 TiO ₂ - 钝化 ATO 支架上的性能进行比较。通过引入基于分子铱的水氧化催化剂，进一步修改了 ATO-PDI 光阳极组件的结构，从而证明了所提出的混合接口作为 PEC 器件中光致氧化光阳极平台的多功能性。