Jian Jing-xin et. al. published a paper on Energy & Environmental Science on April 16, 2016.
Recently, Jian Jing-xin et. al. published a paper onEnergy & Environmental Scienceon April 16, 2016. In this work, we designed two simple water soluble [FeFe]-H2ase mimics Fe2S2-2SO3Na (1) and Fe2S2-SO3Na (2), to construct photocatalytic H2evolution systems in aqueous solution by using molecular Ru(bpy)3Cl2(system I) or CdSe QDs (system II) as PS (Fig. 1). Our results reveal that molecular Ru(bpy)3Cl2systems I showed TONs of 178 for1and 114 for2and initial TOFs of 0.05 s-1for1and 0.02 s-1for2, while CdSe QDs systems II showed more than 100 times larger TONs of 2.65 × 104for1and 1.88 × 104for2, and initial TOF of 3.46 s-1for1and 2.11 s-1for2. Detailed study on mechanism by electrochemical and time-resolved spectroscopic experiments proved that electron transfer could only be allowed between [FeFe]-H2ase mimics and the reduced state [Ru(bpy)3]+through reductive-quenching by sacrificial electron donor rather than excited [Ru(bpy)3]2+. On the contrary, electron transfer can occur directly between CdSe QDs and [FeFe]-H2ase mimics through oxidative-quenching with ketof 7.10 × 1011M-1s-1for1and 3.33 × 1011M-1s-1for2. Further exploration by spectroelectrochemical and transient absorption analysis indicated that the intermediate species [FeIFe0], originated from [FeFe]-H2ase mimics by accepting an electron, could subsequently react with proton to form [FeIFeIIH] species with rate constants calculated to be 1.17 × 107M-1s-1for1and 8.62 × 106M-1s-1for2. All the results suggest that the native properties of PS and its interaction with [FeFe]-H2ase mimic and sacrificial electron donor and proton source greatly affect the performance of the photocatalytic systems, which is the guidance for the sophisticated design of effective photocatalytic H2evolution systems.
