Six donor–donor−π–acceptor (D–D−π–A) triphenylamine-based starburst organic dyes with different electron-donating moieties and thiophene-based π-linkers were synthesized and characterized. Their photophysical and electrochemical properties, together with their photocatalytic hydrogen evolution performance as photosensitizers (PSs), were investigated. Distinctive and prolonged hydrogen evolution performances of these PSs under visible-light irradiation from water in their platinized TiO₂ composites were demonstrated: a turnover number (TON) of up to 24 900 (252 h) with 1560 μmol (37.6 mL) hydrogen produced, an initial turnover frequency (TOF_i) of 1130 h^–1, initial activity (Activity_i) of 705 mmol g^–1 h^–1, and initial apparent quantum yield (AQY_i) of 12.1%. To the best of our knowledge, according to the TOF and TON values, the designed PS system is one of the most efficient and robust photocatalytic H₂ generation systems adopting a TiO₂-anchoring molecular PS in the literature. The results showed that the starburst triarylamine donor moiety with phenothiazine functionality and the alkyl chain on the thiophene π-linker could boost the performance and longevity of the photocatalytic system, providing a powerful strategy for the development of starburst-based highly efficient and robust D–D−π–A organic photosensitizers in the future.

中文翻译：

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用于从水中高效光催化制氢的稳健星爆型有机光敏剂的分子工程

六种供体-供体-π-受体 (D-D-π-A) 三苯胺基星爆有机染料具有不同的给电子部分和噻吩基 π- 接头合成和表征。研究了它们的光物理和电化学性质，以及它们作为光敏剂 (PSs) 的光催化析氢性能。_{证明了这些 PS 在其镀铂 TiO 2}复合材料中在水的可见光照射下具有独特且延长的析氢性能：转换数 (TON) 高达 24 900 (252 h)，产生 1560 μmol (37.6 mL) 氢气，初始周转频率 (TOF _i ) 为 1130 h ^–1，初始活动 (Activity _i ) 为 705 mmol g ^–1 h^–1，初始表观量子产率 (AQY _i ) 为 12.1%。据我们所知，根据 TOF 和 TON 值，所设计的 PS 系统是文献中采用 TiO ₂锚定分子 PS的最有效和最稳健的光催化 H _{2生成系统之一。}结果表明，具有吩噻嗪官能团的星爆三芳胺供体部分和噻吩 π-接头上的烷基链可以提高光催化系统的性能和寿命，为开发基于星爆的高效、稳健的 D- D-π-A 未来的有机光敏剂。