2026-04-13T03:08:28Zhttps://recercat.cat/oai/request

oai:recercat.cat:2072/3057672026-01-15T14:12:32Zcom_2072_300912com_2072_4427col_2072_301309

RECERCAT author Francàs, Laia author Matheu, Roc author Pastor, E. author Reynal, Anna author Berardi, Serena author Sala, Xavier author Llobet, Antoni author Durrant, James 2018-01-15T16:04:20Z2018-02-15T10:27:36Z2024-04-23T10:26:51Z 2018-06-15T00:45:06Z2024-04-23T10:26:51Z 2017 http://hdl.handle.net/2072/305767 https://doi.org/10.1021/acscatal.7b01357 <p> We report an efficient molecular light-driven system to oxidize water to oxygen and a kinetic analysis of the factors determining the efficiency of the system. The system comprises a highly active molecular catalyst ([RuIV(tda)(py)2(O)]), [RuII(bpy)(bpy-COOEt)2]2+ (RuP), as sensitizer and Na2S2O8 as sacrificial electron acceptor. This combination exhibits a high quantum yield (25%) and chemical yield (93%) for photodriven oxygen evolution from water. The processes underlying this performance are identified using optical techniques, including transient absorption spectroscopy and photoluminescence quenching. A high catalyst concentration is found to be required to optimize the efficiency of electron transfer between the oxidized sensitizer and the catalyst, which also has the effect of improving sensitizer stability. The main limitation of the quantum yield is the relatively low efficiency of S2O82– as an electron scavenger to oxidize the photoexcited ruthenium sensitizer RuP* to 2 RuP+, mainly due to competing back electron transfers to the RuP ground state. The overall rate of light-driven oxygen generation is determined primarily by the rate of photon absorption by the molecular sensitizer under the incident photon flux. As such, the performance of this efficient light-driven system is limited not by the properties of the molecular water oxidation catalyst, which exhibits both good kinetics and stability, but rather by the light absorption and quantum efficiency properties of the sensitizer and electron scavenger. We conclude by discussing the implications of these results for further optimization of molecular light-driven systems for water oxidation.</p> eng Copyright © 2017 American Chemical Society Kinetic Analysis of an Efficient Molecular Light-Driven Water Oxidation System info:eu-repo/semantics/article URL https://recercat.cat/bitstream/2072/305767/2/189%20manuscript%20accepted%20article.pdf File MD5 d5c83f7384b29f125c73680f81be0c86 1886816 application/pdf 189 manuscript accepted article.pdf URL https://recercat.cat/bitstream/2072/305767/1/189%20manuscript%20accepted%20article.pdf.txt File MD5 34438fbd32068293f6fb49ee787fd207 47916 text/plain 189 manuscript accepted article.pdf.txt