Research progress on infrared beamline at National Synchrotron Radiation Laboratory

The Hefei light source (HLS) at National Synchrotron Radiation Laboratory (NSRL),China was fully upgraded to HLS II in 2016. Following the machine upgradtion, the infrared beamline was reconstructed to improve its performance. Experimental techniques like variable temperature reflection spectroscopy, in-situ infrared microspectroscopy and high-pressure infrared spectroscopy have been developed for user researches. Here, we summarize some current scientific research progresses at infrared beamline which covers materials science, physics, chemistry and geoscience. They include: (1). Quantum Control of Graphene Plasmon Excitation and Propagation[1]: Quantum mechanical effects of single particles can affect the collective plasmon behaviors substantially. By combining far infrared spectroscopy and near-field infrared microscopy, the quantum control of plasmon excitation and propagation in graphene is demonstrated by adopting the variable quantum transmission of carriers at Heaviside potential steps as a tuning knob. (2). Oxygen electrocatalysis[2]: High-efficiency and low-cost noble-metal-free NiFe MOF-based bifunctional oxygen electrocatalysts were developed by a facile and controllable strategy based on photoinduced lattice strain. Synchrotron infrared operando microscpectroscopy technique was used to probe the catalytic mechanism. The result reveals the formation of a superoxide intermediate and the structural surface evolutions during oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). (3). Hydrogen sites in olivine at high temperature and high pressure[3]: Fingerprinting hydrogen storage sites in olivine at high temperature and high pressure is funda¬mental to understand water distribution and its impact on the upper mantle. By in situ high-temperature and high-pressure infrared spectroscopic techniques, hydrogen storage sites in the natural olivine and synthetic Fe-free forsterite were investigated. We find that hydrogen does not transfer between storage sites with increasing temperature, but displays disordering at temperatures over 600°C. In contrast, pressure can induce re-configuration of hydrogen storage sites corresponding to the 3610 and 3579 cm–1 bands. Hydrogen storage sites also exhibit disordering at high pressure. The disordering and re-configuration of hydrogen storage sites at high temperature and high pressure favor better understanding of the water effects on physical properties of olivine.

[1] Dongli Wang, Xiaodong Fan, Xiaoguang Li. et al. Nano Letters, 18,1373 (2018).
[2] Weiren Cheng, Xu Zhao, Hui Su, et al. Nature Energy, 4, 115 (2019).
[3] Yan Yang, Wendi Liu, Zeming Qi et al. American Mineralogist, 104, 878 ( 2019).