Biomaterial Database

Oligoethylene Glycol Side Chains Increase Charge Generation in Organic Semiconductor Nanoparticles for Enhanced Photocatalytic Hydrogen Evolution. 2022

Jan Kosco, and Soranyel Gonzalez-Carrero, and Calvyn T Howells, and Weimin Zhang, and Maximilian Moser, and Rajendar Sheelamanthula, and Lingyun Zhao, and Benjamin Willner, and Tania C Hidalgo, and Hendrik Faber, and Balaji Purushothaman, and Michael Sachs, and Hyojung Cha, and Rachid Sougrat, and Thomas D Anthopoulos, and Sahika Inal, and James R Durrant, and Iain McCulloch

KAUST Solar Center (KSC), Physical Sciences and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia.

Organic semiconductor nanoparticles (NPs) composed of an electron donor/acceptor (D/A) semiconductor blend have recently emerged as an efficient class of hydrogen-evolution photocatalysts. It is demonstrated that using conjugated polymers functionalized with (oligo)ethylene glycol side chains in NP photocatalysts can greatly enhance their H2 -evolution efficiency compared to their nonglycolated analogues. The strategy is broadly applicable to a range of structurally diverse conjugated polymers. Transient spectroscopic studies show that glycolation facilitates charge generation even in the absence of a D/A heterojunction, and further suppresses both geminate and nongeminate charge recombination in D/A NPs. This results in a high yield of photogenerated charges with lifetimes long enough to efficiently drive ascorbic acid oxidation, which is correlated with greatly enhanced H2 -evolution rates in the glycolated NPs. Glycolation increases the relative permittivity of the semiconductors and facilitates water uptake. Together, these effects may increase the high-frequency relative permittivity inside the NPs sufficiently, to cause the observed suppression of exciton and charge recombination responsible for the high photocatalytic activities of the glycolated NPs.