Hyperion 2000 infrared microscope

Variable-temperature μIR spectroscopic experiments were performed at beamline BL43IR at SPring-8, Japan. A Vertex70 FTIR spectrometer equipped with a Bruker Hyperion 2000 infrared microscope and MCT detector was used. All chemiluminescence, fluorescence and phosphorescence spectra or kinetics were recorded on a Jasco FP8500 spectrofluorimeter equipped with either an ILFC-847S-cooled integration sphere and ESC-842 reference light source for the quantum yield and low-temperature measurements or a ETC-815 temperature cell for the kinetic measurements. The experimental details and additional data are provided as Supplementary Methods.

Transmission spectra of the bare and molecule-coated h-BN arrays were recorded with a Bruker Hyperion 2000 infrared microscope (Bruker Optics GmbH, Ettlingen, Germany) coupled to a Bruker Vertex 70 FTIR spectrometer (Bruker Optics GmbH, Ettlingen, Germany). The normal-incidence infrared radiation from a thermal source (globar) was linearly polarized via wire grid polarizer. The spectral resolution was 2 cm⁻¹.

At the National Synchrotron on Radiation Laboratory’s BL01B infrared beamline, in-situ SR-FTIR analyses utilized a custom-built reflection apparatus with a ZnSe crystal window for infrared transmission, which allows a wavelength pass-through from 20,000 to 440 cm⁻¹ (0.5–23 µm) with a transmittance greater than 68%. The setup included an FTIR spectrometer featuring a KBr beam splitter and multiple detectors, notably a liquid-nitrogen-cooled mercury cadmium telluride detector, integrated with a Bruker Hyperion 2000 infrared microscope and a ×15 magnification objective. A micrometer-thick gap was maintained between the catalyst electrode and the ZnSe window. Initially, the sample was located using a reflection observation mode to focus on the catalyst surface. Measurements were then conducted in a reflection mode with vertical incidence of infrared light. With the light source beam current >400 mA, each infrared absorption spectrum was acquired by averaging 128 scans at a resolution of 4 cm⁻¹. Before measurement, the catalyst electrode’s background spectrum was collected at open-circuit voltage (OCP). The electrocoupling reaction potentials were systematically varied from −0.4 to −0.9 V versus RHE, in steps of 0.1 V. It’s important to note that the instrument automatically subtracted the background obtained at OCP from the test results.