Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, 32000, Israel.
Grand Technion Energy Program, Technion-Israel Institute of Technology, Haifa, 32000, Israel.
Angew Chem Int Ed Engl. 2023 Jul 10;62(28):e202301541. doi: 10.1002/anie.202301541. Epub 2023 Jun 6.
Light is a common source of energy in sustainable technologies for photocurrent generation. To date, in such light-harvesting applications, the excited electrons generate the photocurrent. Here, we introduce a new mechanism for photocurrent generation that is based on excited state proton transfer (ESPT) of photoacids and photobases that can donate or accept a proton, respectively, but only after excitation. We show that the formed ions following ESPT can either serve as electron donors or acceptors with the electrodes, or modify the kinetics of mass transport across the diffuse layer, both resulting in photocurrent generation. We further show that control of the current polarity is obtained by switching the irradiation between the photoacid and the photobase. Our study represents a new approach in photoelectrochemistry by introducing ESPT processes, which can be further utilized in light-responsive energy production or energy storage.
光是可持续技术中用于光电流产生的常见能源。迄今为止，在这种光收集应用中，激发电子产生光电流。在这里，我们介绍了一种基于光酸和光碱的激发态质子转移（ESPT）的新型光电流产生机制，光酸和光碱分别可以提供或接受质子，但只能在激发后。我们表明，ESPT 形成的离子可以作为电子供体或受体与电极结合，或者改变扩散层中质量传输的动力学，从而产生光电流。我们进一步表明，通过在光酸和光碱之间切换照射，可以控制电流极性。我们的研究通过引入 ESPT 过程代表了光电化学的一种新方法，该方法可进一步用于响应光的能量产生或能量存储。
