Oligoethylene glycol sidechains increase charge generation in organic semiconductor nanoparticles for enhanced photocatalytic hydrogen evolution

Journal article

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.

Authors: Kosco, J; Gonzalez-Carrero, S; Howells, CT; Zhang, W; Moser, M

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Advanced Materials
• Volume: 34
• Issue: 22
• Article number: 2105007
• Place of publication: Germany
• Publication date: 2021-11-26
• Acceptance date: 2021-10-29
• DOI: 10.1002/adma.202105007
• EISSN: 1521-4095
• ISSN: 0935-9648
• Pmid: 34714562
• Language: English
• Keywords: hydrogen; solar fuels; nanoparticles; photocatalysts; organic semiconductors; FFR