Homogenous photocatalytic systems based on copper photosensitizers are promising candidates for noble metal free approaches in solar hydrogen generation. To improve their performance a detailed understanding of the individual steps is needed. Here, we study the interaction of a heteroleptic copper (I) photosensitizer with an iron catalyst by time-resolved spectroscopy and ab-initio calculations. The catalyst leads to rather efficient quenching of the ³MLCT state of the copper complex, with a bimolecular rate being about three times smaller than the collision rate. Using control experiments with methyl viologen an appearing absorption band is assigned to the oxidized copper complex demonstrating that electron transfer from the sensitizer to the iron catalyst occurs and the system reacts along an oxidative pathway. However, only about 30% of the quenching events result in an electron transfer while the other 70% experience deactivation indicating that the photocatalytic performance might suffer from geminate recombination.

基于铜光敏剂的均相光催化系统有望成为太阳能制氢中无贵金属方法的候选者。为了提高其性能，需要对各个步骤有详细的了解。在这里，我们通过时间分辨光谱和从头算计算研究了杂铜（I）光敏剂与铁催化剂的相互作用。催化剂导致^3的高效淬火铜络合物的MLCT状态，双分子速率比碰撞速率小三倍。使用甲基紫精的对照实验，将出现的吸收带分配给氧化的铜络合物，表明发生了从敏化剂到铁催化剂的电子转移，并且系统沿着氧化途径发生反应。但是，只有约30％的猝灭事件会导致电子转移，而其他70％的则发生失活，这表明光催化性能可能会发生萌芽重组。