Fig. 4: Identification of the active sites and reactive species.
From: Near-infrared photon-triggered CH4-to-CH3OH conversion over plasmonic oxyselenides
a OCP response under illumination and in the dark. In situ high-resolution (b) Au 4 f and (c) Cu 2p XPS spectra, as well as (d) in situ EPR spectra for Au/CuSeO2.82 in the dark and under light irradiation. In situ EPR spectra of (e) DMPO-OH and (f) DMPO-OOH over different photocatalysts under light illumination. g Fluorescence spectra of the coumarin aqueous solution dispersed with Au/CuSeO2.82 under light irradiation in O2 or Ar atmosphere. Insets: the detection mechanism of •OH by coumarin. h In situ EPR spectra of DMPO-OH and DMPO-CH3 over Au/CuSeO2.82 under light illumination in the presence of sacrificial agent or not. TEOA is used for consuming photogenerated holes, and IPA is used for consuming photogenerated holes and •OH radicals simultaneously. i Illustration of the band structure determined for Au/CuSeO2.82 and the redox potentials for different radicals. Source data for a–h are provided as a Source Data file.
