Light-Triggered Reversible Change in the Electronic Structure of MoO 3 Nanosheets via an Excited-State Proton Transfer Mechanism

• Published in: Nano letters Vol. 24; no. 6; p. 1936
• Main Authors: Gilad Barzilay, Yuval, Yucknovsky, Anna, Amdursky, Nadav
• Format: Journal Article
• Language: English
• Published: United States 14-02-2024
• Subjects: plasmon resonance; pyranine; molybdenum oxide; nanosheets
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.3c04209

Light is an attractive source of energy for regulating stimulus-responsive chemical systems. Here, we use light as a gating source to control the redox state, the localized surface plasmonic resonance (LSPR) peak, and the structure of molybdenum oxide (MoO
) nanosheets, which are important for various applications. However, the light excitation is not that of the MoO
nanosheets but rather that of pyranine (HPTS) photoacids, which in turn undergo an excited-state proton transfer (ESPT) process. We show that the ESPT process from HPTS to the nanosheets and the intercalation of protons within the MoO
nanosheets trigger the reduction of the nanosheets and the broadening of the LSPR peak, a process that is reversible, meaning that in the absence of light, the LSPR peak diminishes and the nanosheets return to their oxidized form. We further show that this reversible process is accompanied by a change in the nanosheet size and morphology.