π-Conjugated Organic–Inorganic Hybrid Photoanodes: Revealing the Photochemical Behavior through In Situ X-Ray Absorption Spectroscopy
Journal
Chemistry - A European Journal
Journal Volume
24
Journal Issue
69
Pages
18419-18423
Date Issued
2018
Author(s)
Abstract
Small-molecule organic semiconductors exhibit great potential for the photoelectrochemical oxidation of water because of their n-type semiconductor nature and their tunable bandgaps. In this work, several head-to-tail bis-coumarins were synthesized and their photophysical properties characterized. Their characteristics as n-type semiconductors were modified by varying the electronic character of substituents at positions 1 and 7, which enabled the energy level of the LUMO and the photoinduced charge-carrier-transfer efficiency to be modulated. X-Ray absorption near-edge structure (XANES) spectroscopy confirmed that the charge transfer is a crucial factor contributing to the resulting activity of the photoanode. The photoactivity of the photoanodes towards water oxidation was revealed to be governed by both the LUMO energy level and transfer efficiency of the photoinduced charge carriers. Among the studied molecules, a bis-coumarin with benzothiophenyl substituents showed the greatest potential as light absorber for photoelectrochemical water oxidation. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Subjects
heterocycles; photoanode; small-molecule semiconductor; X-ray absorption
SDGs
Other Subjects
Charge carriers; Charge transfer; Electrochemistry; Molecules; Oxidation; X ray absorption; X ray absorption near edge structure spectroscopy; Heterocycles; In-situ X-ray absorption spectroscopy; Photo-anodes; Photo-electrochemical oxidations; Photoelectrochemical water oxidation; Photoinduced charge carriers; Small molecules; Small-molecule organic semiconductor; Energy efficiency
Type
journal article