Research Highlights
Hung-Sheng Tsai, Chih-En Shen, Sheng-Chieh Hsu, and Liang-Yan Hsu*
J. Phys. Chem. Lett. 14, 25, 5924–5931 (2023).
To explore non-adiabatic effects caused by electromagnetic (EM) vacuum fluctuations in molecules, we develop a general theory of internal conversion (IC) in the framework of quantum electrodynamics and propose a new mechanism, “quantum electrodynamic internal conversion” (QED-IC). The theory allows us to compute the rates of the conventional IC and QED-IC processes at the first-principles level. Our simulations manifest that, under experimentally feasible weak light–matter coupling conditions, EM vacuum fluctuations can significantly affect IC rates by an order of magnitude. Moreover, our theory elucidates three key factors in the QED-IC mechanism: the effective mode volume, coupling-weighted normal mode alignment, and molecular rigidity. The theory successfully captures the nucleus–photon interaction in the factor “coupling-weighted normal mode alignment”. In addition, we find that molecular rigidity plays a totally different role in conventional IC versus QED-IC rates. Our study provides applicable design principles for exploiting QED effects on IC processes.
Dr. Charles Pin-Kuang Lai
(2023)
Bryan John Abel Magoling,
Anthony Yan-Tang Wu,
Yen-Ju Chen,
Wendy Wan-Ting Wong,
Steven Ting-Yu Chuo,
Hsi-Chien Huang,
Yun-Chieh Sung,
Hsin Tzu Hsieh,
Poya Huang,
Kang-Zhang Lee,
Kuan-Wei Huang,
Ruey-Hwa Chen,
Yunching Chen,
Charles Pin-Kuang Lai
Advanced Materials. https://doi.org/10.1002/adma.202208966 (2023).
Our latest publication employed PalmGRET, a bioluminescence-resonance-energy-transfer (BRET)-based EV reporter, to discover an abundant release of big EVs (bEVs; >200 nm) by aggressive breast cancers when compared to epithelial and less malignant cells. bEVs have been largely overshadowed by small EVs (sEVs; <200 nm) in EV research in the past decades. This is the first study to accurately detect and systematically compare biophysical property and in vivo profiles of breast cancer bEVs and sEVs. This is followed by the identification of EV surface oncoproteins, and their role in modulating organotropism and tumorigenic potential of the bEVs and sEVs. Our landmark findings impart a broad and deep reference for upcoming EV studies, with an emphasis on EV engineering for diagnosis and therapeutic applications.
Chih-Yi Cheng, Wei-Liang Pai, Yi-Hsun Chen, Naomi Tabudlong Paylaga, Pin-Yun Wu, Chun-Wei Chen, Chi-Te Liang, Fang-Cheng Chou, Raman Sankar, Michael S. Fuhrer, Shao-Yu Chen*, and Wei-Hua Wang*
Nano Lett., 22, 6, 2270–2276 (2022).
Understanding the Coulomb interactions between two-dimensional (2D) materials and adjacent ions/impurities is essential to realizing 2D material-based hybrid devices. Electrostatic gating via ionic liquids (ILs) has been employed to study the properties of 2D materials. However, the intrinsic interactions between 2D materials and ILs are rarely addressed. This work studies the intersystem Coulomb interactions in IL-functionalized InSe field-effect transistors by displacement current measurements. We uncover a strong self-gating effect that yields a 50-fold enhancement in interfacial capacitance, reaching 550 nF/cm2 in the maximum. Moreover, we reveal the IL-phase-dependent transport characteristics, including the channel current, carrier mobility, and density, substantiating the self-gating at the InSe/IL interface. The dominance of self-gating in the rubber phase is attributed to the correlation between the intra- and intersystem Coulomb interactions, further confirmed by Raman spectroscopy. This study provides insights into the capacitive coupling at the InSe/IL interface, paving the way to developing liquid/2D material hybrid devices.
Dr. Kuei-Hsien Chen
(2022)
Amr Sabbah, Indrajit Shown*, Mohammad Qorbani, Fang-Yu Fu, Tsai-Yu Lin, Heng-Liang Wu, Po-Wen Chung, Chih-I. Wu, Svette Reina Merden Santiago, Ji-Lin Shen, Kuei-Hsien Chen*, Li-Chyong Chen*
Nano Energy, 93, 106809 (2022).
Employing direct Z-scheme semiconductor heterostructures in photocatalysis offers efficient charge carrier separation and isolation of both redox reactions, thus beneficial to reduce CO2 into solar fuels. Here, a ZnS/ZnIn2S4 heterostructure, comprising cubic ZnS nanocrystals on hexagonal ZnIn2S4 (ZIS) nanosheets, is successfully fabricated in a single-pot hydrothermal approach. The composite ZnS/ZnIn2S4 exhibits microstrain at its interface with an electric field favorable for Z-scheme. At an optimum ratio of Zn:In (~ 1:0.5), an excellent photochemical quantum efficiency of around 0.8% is reached, nearly 200-fold boost compared with pristine ZnS. Electronic levels and band alignments are deduced from ultraviolet photoemission spectroscopy and UV-Vis. Evidence of the direct Z-scheme and carrier dynamics is verified by photo-reduction experiment, along with photoluminescence (PL) and time-resolved PL. Finally, diffuse-reflectance infrared Fourier transformed spectroscopy explores the CO2 and related intermediate species adsorbed on the catalyst during the photocatalytic reaction. This microstrain-induced direct Z-scheme approach opens a new pathway for developing next-generation photocatalysts for CO2 reduction.
Yu-Chen Wei and Liang-Yan Hsu*
Journal of Physical Chemistry Letters, 13, 9695–9702 (2022).
Richard Feynman stated that “The theory behind chemistry is quantum electrodynamics”. However, harnessing quantum-electrodynamic (QED) effects to modify chemical reactions is a grand challenge and currently has only been reported in experiments using cavities due to the limitation of strong light–matter coupling. In this article, we demonstrate that QED effects can significantly enhance the rate of electron transfer (ET) by several orders of magnitude in the absence of cavities, which is implicitly supported by experimental reports. To understand how cavity-free QED effects are involved in ET reactions, we incorporate the effect of infinite one-photon states into Marcus theory, derive an explicit expression for the rate of radiative ET, and develop the concept of “electron transfer overlap”. Moreover, QED effects may lead to a barrier-free ET reaction whose rate is dependent on the energy-gap power law. This study thus provides new insights into fundamental chemical principles, with promising prospects for QED-based chemical reactions.