Organic conjugated molecules are a category of high solar harvesting material that can convert energy into heat and be utilized as solar-driven water-electricity co-generation. However, the limited absorption range and insufficient photothermal conversion efficiency hinder their application. Herein, two new organic molecules TPA-BTQ and TPA-SBTQ, featuring strong electron withdrawing [1,2,5]thiadiazolo[3,4-g]quinoxaline-6,7-dicarboxylate (BTQ) center, terminated by triphenylamine or thiophene-bridged triphenylamine are designed and synthesized. Detailed theory calculations and spectral analysis confirm that the BTQ unit induces strong intramolecular charge transfer and expands the absorption across a wide spectra range. The flexible alky chain substituted on thiophene inhibits the over-aggregation and affords more rotation space, leading to suppressed radiative transition and efficient solar-thermal conversion. Therefore, TPA-SBTQ powder shows broad absorption across 350 to 1300 nm with a high photothermal conversion efficiency of 18.28% under 1 kW m⁻² simulated solar irradiation. Moreover, TPA-SBTQ is further explored for solar-thermal conversion applications. The evaporation rate of TPA-SBTQ solar-driven water evaporator can reach a remarkable 1.337 kg m⁻² h⁻¹ with 92% of water evaporation efficiency under 1 kW m⁻² solar irradiation. This study provides guidance for the rational design of high-efficient organic solar-thermal materials with a wide absorption spectrum and excellent photothermal conversion efficiency at the molecular level for emerging photothermal-related applications.

中文翻译：

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操纵[1,2,5]噻二唑并[3,4-g]喹喔啉-6,7-二羧酸酯小分子的分子运动实现高效太阳能热水蒸发和热电发电


有机共轭分子是一类高太阳能收集材料，可以将能量转化为热能并用于太阳能驱动的水电联产。然而，有限的吸收范围和不足的光热转换效率阻碍了它们的应用。在此，两种新的有机分子TPA-BTQ和TPA-SBTQ具有强吸电子[1,2,5]噻二唑并[3,4-g]喹喔啉-6,7-二羧酸酯（BTQ）中心，由三苯胺或噻吩封端设计并合成了桥联三苯胺。详细的理论计算和光谱分析证实，BTQ 单元会引起强烈的分子内电荷转移，并将吸收范围扩大到很宽的光谱范围。噻吩上取代的柔性烷基链抑制了过度聚集并提供了更多的旋转空间，从而抑制了辐射跃迁并实现了高效的太阳热转换。因此，TPA-SBTQ粉末在350至1300 nm范围内表现出广泛的吸收，在1 kW m ⁻² 模拟太阳辐射下，光热转换效率高达18.28%。此外，TPA-SBTQ 还进一步探索了太阳能热转换应用。 TPA-SBTQ太阳能水蒸发器的蒸发量可达到惊人的1.337 kg m ⁻² h ⁻¹ ，在1 kW m ⁻²