Biradical-Featured Stable Organic-Small-Molecule Photothermal Materials for Highly Efficient Solar-Driven Water Evaporation

作者：Chen, Guanyu; Sun, Jiangman; Peng, Qian; Sun, Qi; Wang, Guan; Cai, Yuanjing; Gu, Xinggui^*; Shuai, Zhigang; Tang, Ben Zhong^*

来源：Advanced Materials, 2020, 32(29): 1908537.

DOI：10.1002/adma.201908537

• biradical character
• croconium dyes
• photothermal conversion
• solar-driven water evaporation

With recent progress in photothermal materials, organic small molecules featured with flexibility, diverse structures, and tunable properties exhibit unique advantages but have been rarely applied in solar-driven water evaporation owing to limited sunlight absorption resulting in low solar-thermal conversion. Herein, a stable croconium derivative, named CR-TPE-T, is designed to exhibit the unique biradical property and strong pi-pi stacking in the solid state, which facilitate not only a broad absorption spectrum from 300 to 1600 nm for effective sunlight harvesting, but also highly efficient photothermal conversion by boosting nonradiative decay. The photothermal efficiency is evaluated to be 72.7% under 808 nm laser irradiation. Based on this, an interfacial-heating evaporation system based on CR-TPE-T is established successfully, using which a high solar-energy-to-vapor efficiency of 87.2% and water evaporation rate of 1.272 kg m(-2) h(-1) under 1 sun irradiation are obtained, thus making an important step toward the application of organic-small-molecule photothermal materials in solar energy utilization.

• 单位
  北京化工大学; 中国科学院; 清华大学