Although the importance of nonphotochemical quenching (NPQ) on photosynthetic biomass production and crop yields is well established, the in vivo operation of the individual mechanisms contributing to overall NPQ is still a matter of controversy. In order to investigate the timescale and activation dynamics of specific quenching mechanisms, we have developed a technique called snapshot transient absorption (TA) spectroscopy, which can monitor molecular species involved in the quenching response with a time resolution of 30 s. Using intact thylakoid membrane samples, we show how conventional TA kinetic and spectral analyses enable the determination of the appropriate wavelength and time delay for snapshot TA experiments. As an example, we show how the chlorophyll-carotenoid charge transfer and excitation energy transfer mechanisms can be monitored based on signals corresponding to the carotenoid (Car) radical cation and Car S₁ excited state absorption, respectively. The use of snapshot TA spectroscopy together with the previously reported fluorescence lifetime snapshot technique (Sylak-Glassman et al. in Photosynth Res 127:69-76, 2016) provides valuable information such as the concurrent appearance of specific quenching species and overall quenching of excited Chl. Furthermore, we show that the snapshot TA technique can be successfully applied to completely intact photosynthetic organisms such as live cells of Nannochloropsis. This demonstrates that the snapshot TA technique is a valuable method for tracking the dynamics of intact samples that evolve over time, such as the photosynthetic system in response to high-light exposure.

A platinum catalyst supported on zirconia is proposed as a cathode in lithium-oxygen batteries. Experimental and theoretical studies show that zirconia suppresses the side-reactions of the intermediate (O2-) and the final product (Li2O2) by the stabilization of their reactivity. Thus, it is able to enhance the reversibility during charge/discharge in lithium-oxygen batteries.

A graphene sulfide framework (GSF) is designed and synthesized via a hybridization of graphene and organic compounds for use in electrodes for high-performance Li-ion batteries (LIB). This electrode material is devoid of transition metal and features a layered framework structure that is constructed by the formation of covalent disulfide bonds between organic linker molecules and graphene sheets. This structure capitalizes on the advantageous properties of each of the components in an electrochemical reaction. The structures of GSFs are characterized by Cs-corrected transmission electron microscopy (Cs-TEM), field emission scanning electron microscopy (FE-SEM), and X-ray diffraction (XRD). Depending on current density, the GSF electrodes exhibit two different types of electrochemical behavior during Li incorporation/extraction process, indicating the involvement of multiple Li-incorporation mechanisms. Various types of dithiol organics as linker components are incorporated in the GSF to evaluate the effect of length or structure on the electrochemical properties. The linker-dependent Li storage mechanism is explained based on the results of differential capacity analyses and electrochemical impedance spectroscopy (EIS). The GSF proposed in this study shows promise as an electrode material for a high-performance energy-storage system that is inexpensive and free of transition metals.

As electronic devices have continued to advance, consistent with Moore's law, it is clear that the development of technology can create new types of products and jobs and even industrial sectors. While human integrated devices, storage of fluctuating energy sources and electric transports are required in the near future, one field of electronics has not fully developed,-i.e., energy storage devices. In order to overcome this impediment, we developed a new approach of energy systems that is inspired by the difference in evolutionary genealogy between animals, i.e., insects (exoskeleton) versus vertebrates (endoskeleton). The new energy storage technology proposed here includes an endoskeleton architecture similar to vertebrates, which (1) provides flexibility for future mobile/human integrated electrics, (2) ensures the scalability of devices for the storage of fluctuating energy sources and (3) solves safety issues associated with energy storage devices in electric vehicles.

Real-time analysis of changes in the atomic environment of materials is a cutting edge technology that is being used to explain reaction dynamics in many fields of science. Previously, this kind of analysis was only possible using heavy nucleonic equipment such as XANES and EXAFS, or Raman spectroscopy on a moderate scale. Here, a new methodology is described that can be used to track changes in crystalline developments during complex Li insertion reactions via the observation of structural color. To be specific, the changes in atomic crystalline and nanostructure are shown during Li insertion in a complex TiO₂ polymorph. Structural color corresponds to the refractive indices of materials originating from their atomic bonding nature and precise wave interferences in accordance with their nanostructure. Therefore, this new analysis simultaneously reveals changes in the nanostructure as well as changes in the atomic bonding nature of materials.

The rapid response of photosynthetic organisms to fluctuations in ambient light intensity is incompletely understood at both the molecular and membrane levels. In this review, we describe research from our group over a 10-year period aimed at identifying the photophysical mechanisms used by plants, algae and mosses to control the efficiency of light harvesting by photosystem II on the seconds-to-minutes time scale. To complement the spectroscopic data, we describe three models capable of describing the measured response at a quantitative level. The review attempts to provide an integrated view that has emerged from our work, and briefly looks forward to future experimental and modelling efforts that will refine and expand our understanding of a process that significantly influences crop yields.

There has been an unsolvable bottleneck in energy storage wires, with greatly diminished energy even when the most advanced materials are used. Here, the bottleneck is proved using analytical derivation, which is referred as an "energy lag effect." To solve the effect, a new-type energy storage wires are designed, including a dual planar-helix structure. The systems do not show any energy lagging, experimentally or analytically.

Dodecatitanate H2Ti12O25 crystal has a condensed layered structure and exhibits noteworthy Li storage performance that makes it an anode material with great potential for use in Li-ion batteries. However, an unknown Li diffusion mechanism and a sluggish level of Li dynamics through elongated diffusion paths inside this crystal has impeded any forward development in resolving its limited rate capability and cyclic stability. In this study, we investigated the Li diffusion dynamics inside the H2Ti12O25 crystal that play an essential role in Li storage performance. A study of density functional theory combined with experimental evaluation confirmed a strong dependence of Li storage performance on its diffusion. In addition, a nanostructured H2Ti12O25 containing a bundle of nanorods is developed via the introduction of a kinetic gap during the structural transformation, which conferred a significantly shortened diffusion time/length for Li in H2Ti12O25. The nanostructured H2Ti12O25 has high specific capacity (∼230 mAh g(-1)) and exhibits enhanced cyclic stability and rate capability compared with conventional bulky H2Ti12O25. The H2Ti12O25 proposed in this study has high potential for use as an anode material with excellent safety and stability.

Nonphotochemical quenching mechanisms regulate light harvesting in oxygenic photosynthesis. Measurement techniques for nonphotochemical quenching have typically focused on downstream effects of quenching, such as measuring reduced chlorophyll fluorescence. Here, to directly measure a species involved in quenching, we report snapshot transient absorption (TA) spectroscopy, which rapidly tracks carotenoid radical cation signals as samples acclimate to excess light. The formation of zeaxanthin radical cations, which is possible evidence of zeaxanthin-chlorophyll charge-transfer (CT) quenching, was investigated in spinach thylakoids. Together with fluorescence lifetime snapshot data and time-resolved high-performance liquid chromatography (HPLC) measurements, snapshot TA reveals that Zea^•+ formation is closely related to energy-dependent quenching (qE) in nonphotochemical quenching. Quantitative and dynamic information on CT quenching discussed in this work give insight into the design principles of photoprotection in natural photosynthesis.

Despite the many efforts to solve the problem associated with lithium storage at high rates, it is rarely achieved up until now. The design with experimental proof is reported here for the high rate of lithium storage via a core-shell structure composite comprised of a Li4Ti5O12 (LTO) core and a nanographene (NG) shell. The LTO-NG core-shell was synthesized via a first-principles understanding of the adsorption properties between LTO and NG. Interfacial reactions are considered between the two materials by a redox coupling effect. The large interfacial area between the LTO core and the NG shell resulted in a high electron-conducting path. It allowed rapid kinetics to be achieved for lithium storage and also resulted in a stable contact between LTO and NG, affording cyclic performance stability.