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In recent years, there has been a growing demand for safe soft robots that work in a work environment similar to that of humans. The use of 3D modeling technology in the manufacturing of soft robot chassis, soft electronic parts, and wiring processes is expected to lead to more efficient and smaller soft robot manufacturing. The objective of this study is to fabricate a gel capacitor using ionic liquid as an electrolyte, which has characteristics such as non-volatility, flame retardance, and conductivity. We fabricate ionic liquid gels that possess flexibility and conductivity after curing using a photoformable 3D gel printer, and discuss their performance as capacitors.

We often come across differences in the severity of androgenetic alopecia (AGA) as assessed subjectively by the patients themselves and objectively by the attending physicians. For the purpose of examining the differences in the assessment of AGA between patients and physicians, we presented the Norwood classification to male patients and the Shiseido classification to female patients and asked them to assess the degree of hair loss by themselves. We compared the results with the severity as assessed by 2 specified dermatologists. The results show that the assessments of the severity of AGA were consistent between the patients and physicians in 42% (15/36) of cases, the physicians reported a higher grade of severity than the patients themselves in 30% (11/36) of cases, and the patients reported a higher grade of severity than the physicians in 28% (10/36) of cases; however, the Wilcoxon signed rank statistical analysis showed no significant difference between the patients and physicians assessments. AGA should be treated in accordance with individual symptoms and wishes and not a standardized treatment protocol.

Copper(I) thiocyanate (CuSCN) is known as a wide bandgap p-type semiconductor and recently demonstrated its high ability as a hole-transporting material in perovskite solar cells and light emitting diodes. Its thin film is usually fabricated by simple solution coating and drying [1]. In fact, little is known for physical properties of CuSCN, such as bandgap, band positions, optical transparency, carrier density and mobility. We have established methods to electrodeposit well-crystallized CuSCN thin films in various forms. Although the electrochemistry is fairly simple as limited by diffusion of 1 : 1 complex between Cu2+ and SCN- ions ([Cu(SCN)]+), the [Cu2+] : [SCN-] ratio, its absolute concentration and solvent can significantly alter the morphology and crystal orientation of resulting CuSCN [2]. These unique features of the electrodeposition technique let us anticipate possibilities to tailor-tune physical properties of CuSCN to match the demands for device applications. In this study, we have carried out electrodeposition of CuSCN to vary its morphology and crystal orientation by tuning the bath composition and studied their band structure to explore the room for tuning its physical properties for thin film diodes and hybrid electroluminescence devices. Morphologies of CuSCN thin films electrodeposited from stoichiometric (REF), Cu-rich and SCN-rich baths are shown in Figs. 1 a-c. While the REF sample has an open structure made of relatively large bulky particles, the Cu-rich sample is dense, made of tiny grains to expose their hexagonally shaped top. On the other hand, the one from the SCN-rich bath show rectangular sides of the grains (Fig. 1 a) and strongly oriented to lay down the c-axis in parallel with the substrate. XRD patterns have found almost parallel orientation for the SCN-rich and a high degree of preference of the Cu rich to orient the c-axis of β-CuSCN perpendicular to the substrate. Although all these films indicate nearly the same energy gap of about 3.6 eV estimated by Tauc plot, significant difference was found for their work function (WF) measured by photoelectron yield spectroscopy (PYS) (Fig. 2). The threshold energy moved downwards from 5.23 to 5.66 eV vs. VAC from Cu-rich to SCN-rich film. The result indicates a high level of p-type doping in the presence of excess SCN-, probably due to increased concentration of Cu2+ as stabilized by SCN- bound to it. Simple devices as ITO / electrodeposited CuSCN / Aluminium were fabricated to examine their diode behaviour. While all of the devices employing the electrodeposited CuSCN thin films showed good rectifications in the J-V curves, the onset voltage determined that to observe 5 mA/cm2 moved from 1.21 to 2.57 V (ITO being positive) from Cu-rich to SCN-rich samples to confirm tunability of the device property by conditions of the electrodeposition. Successful operation of organic light emitting diode was also achieved by employing the electrodeposited CuSCN as a hole-injection layer. The device employing the electrodeposited CuSCN achieved a smaller turn-on voltage than that with spin-coated CuSCN in the I-V-L measurements. [1] Vinod E. Madhavan et al., ACS Energy Lett. 2016, 1, 1112−1117. [2] Lina Sun et al., Physics Procedia, 2011, 14, 12-24. Figure 1

While electric power supply by renewable sources such as solar and wind has become viable for their significant cost reduction, its intermittency demands urgent development of large scale storage technologies. Although conversion of electrical energy into storable hydrogen via electrolysis of water is ideal, noble metals and their oxides are used as electrocatalysts for their activities and stabilities. Alternative electrocatalysts out of abundant elements are needed for sustainable technological development. Recently, some metal-free organic conductive polymers with hydrogen-bonding capabilities were found to exhibit high electrocatalytic activities towards hydrogen evolution reaction (HER) [1,2]. We have succeeded electropolymerization of neutral red (NR) resulting in a formation of conductive poly-NR (PNR) that shows a relatively high HER catalytic activity [3]. PNR possesses hydrogen-bonding N atoms as annelated in the phenazine aromatic system as well as those in the amino substituents. Electrochemical analysis combined with in situ spectroscopy as well as DFT calculation was performed to clarify the mechanism and kinetics of HER electrocatalysis by PNR. This films of PNR were obtained by electropolymerization on F-doped SnO2 coated conductive glass (FTO, Asahi Glass) and SIGRATHERM® GFA5 Carbon felt with potential cycling between -0.2 and 1.2 V (vs. Ag/AgCl) at 50 mV s-1 for 50 times in a 5 mM NR - 0.1 M H2SO4 aqueous solution under N2. Polyaniline (PANI) was also obtained by the same method for comparison. The HER catalysis was evaluated by linear sweep voltammetry (LSV) in a 1 M trifluoromethanesulfonic acid (TfOH) under N2. The film samples were characterized by Fourier transform infrared spectroscopy (FT-IR), UV-visible spectroscopy. In-situ UV-visible spectroelectrochemical monitoring of the reaction intermediate was carried out to determine the rate of HER. PNR undergoes a pseudo-reversible reduction that shifts -61.8 mV/pH under acidic conditions and HER takes off right at this point (Fig. 1, a). Coupling of the same number of protons / electrons is expected as the electrochemical stoichometry from the observed Nernstian relationship, namely, resulting in a singly reduced PNR-H or doubly reduced PNR-H2 as depicted in Fig. 1 b. Protonation of N atoms was reasonably expected and also supported by the DFT calculation. The hydrogen atoms stabilized in the reaction intermediate can be associated to release H2 (Tafel mechanism) to complete the cycle of electrocatalysis of HER. Reduction of PNR in fact is associated with a color change. The broad reddish absorption of PNR peaking at around 500 nm attenuates to change the color to a pale yellow by constantly applying -0.15 V vs. RHE to produce PNR-H and/or PNR-H2 state as shown in Fig. 1c. Gradual recovery of the original red PNR was observed under open circuit under N2, associated with the H2 release. Thus, the rate of the spectral change is analyzed to determine the rate of the Tafel process. Pseudo-first order reaction rate law can be applied as proton is abundant and its concentration is constant, so that the rate of HER (r H2) is simply described as the rate of consumption of PNR-H and/or PNR-H2 as, r H2=-dC PNR-H2/dt =-kt (1) The ratio of PNR-H and PNR-H2 as compared to their initial amount (x PNR-red) was defined from the absorbance at 545 nm before and after reduction as, x PNR-red = C PNR-red/C 0-PNR-red = exp (-kt) (2) Good fitting of the experimental data was obtained to yield a pseudo-first order reaction rate constant of 9.98×10-4 s-1 for this rate-limiting step. References [1] H. Coskun et al. Advanced Materials 32, 1902177 (2020). [2] H. Coskun et al. Advanced Materials Interfaces 7, 1901364 (2020). Figure 1

Hydrogen bonding conductive polymers have attracted attention as metal-free electrocatalysts for energy conversion (1)(2). Neutral red (NR), a pH indicator in the family of phenazine dyes, can be polymerized into poly-NR (PNR) just like aniline (ANI) does into poly-ANI (PANI). Due to the presence of hydrogen bonding N atom, PNR has been found to act as a good catalyst for hydrogen evolution reaaction (HER) (3). Although electropolymerization to achieve these polymer films is believed to take off by oxidation of the monomers into their respective radicals, potential sweep and cycling in a wide potential range are almost always employed, in other words, the films are obtained in the course of cyclic voltammetry (CV) in the monomer solutions. A clear benefit of such a method is to facilitate monitoring of the film growth, as the electrodeposited polymers often show a redox behavior. However, it is not easy to elucidate electrochemical stoichiometry and its Faradic efficiency by charge integration from the CVs during the film growth. If the electrochemical oxidation of the monomers is the only important process, potentiostatic electrolysis and chronoamperometric (CA) monitoring should work as well and be beneficial to the understanding of the reaction mechanism. However, to our knowledge, no such studies have been reported so far. In this study, several different protocols of electrolysis have been tested and compared for electropolymerization of NR, i.e., potential sweep/cycling (CV), potentiostatic electrolysis (CA), potential stepping pulsed electrolysis (PP), with variation of conditions and also by their combinations. While reddish black thin films of PNR were nicely obtained by the standard CV method up to +1.2 V vs. Ag/AgCl to oxidize NR and down to -0.2 V to observe reduction of NR as well as electrodeposited PNR in acidic aqueous solutions of NR + H2SO4, the CA method to apply a constant potential of +1.05 V, sufficiently positive to promote oxidation of NR resulted in in a significant slowdown of PNR growth. The CA method, however, did result in a formation of PNR. Comparison of anodic charge for monomer oxidation both in the CV and CA methods with the optical density (O.D.) of the resulting PNR proved proportionality of O.D. to charge with the same O.D./charge ratios, thus the same Faradic efficiencies. In fact, CA showed a drastic decrease of current down to a rather small steady-state value. This was not caused by depletion of NR at the vicinity of the electrode, but by slowdown of charge transfer kinetics, as the introduction of forced convection by employing a rotating disk electrode (RDE) did not result in any enhancement of current. On the other hand, the anodic peak current only slightly decreased over multiple potential cycling in the CV method. The peak current was approximately linearly proportional to the square root of the scan rate, so that fast charge transfer to hit the diffusion limit of NR was achieved in the CV method. The cause of the difference of charge transfer kinetics was further studied. Anodic growth of PNR naturally results in doping of anions, in this case sulfate, to stabilize polarons to achieve conductivity of PNR. Careful observation of CVs found presence of a couple of small peaks which correspond to doping / dedoping at around +0.5 V. Electrodeposition of PNR by the CV method with variation of negative end potential revealed the importance of dedoping of sulfate to refresh the surface of PNR to be favorable to the oxidation of NR, not the reduction /re-oxidation of the existing PNR. Thus, the PP method to switch the potential between that for the oxidation of NR monomer and the one for dedoping of sulfate from PNR (not the reduction of PNR) achieved the fastest growth of PNR. The above-documented understanding of the electropolymerization of NR will be explained in a quantitative manner along with the experimental data. It is also interesting to mention the difference of the absorption spectra of the PNR films between those obtained by CV and CA methods, indicating their differences in the electronic structure to let us anticipate their differences in the HER electrocatalysis. Reference: Coskun H. al.，Adv. Mater. 32, 25, e1902177 (2020). Coskun H. et. al.， Sustainable Syst. 5, 25, 2000176 (2021). Yuya H al.，The ECS spring meeting abstract 1A17 (2021).

The terrestrial ciliated protozoan Colpoda cucullus inhabits soil. When the habitat conditions become unfavorable, the vegetative cells of C. cucullus quickly transform into resting cysts. C. cucullus culture is established in our laboratory, and encystment is routinely induced by the addition of Ca2+ to overpopulated vegetative cells. However, an increase in Ca2+ concentration and overpopulation of vegetative cells do not always occur in natural. We investigated the effect of temperature and found that cyst formation was induced by a rapid increase of 5 °C within 2 min but not by a decrease. Moreover, an increase in intracellular Ca2+ concentrations is essential, but Ca2+ inflow does not necessarily occur during encystment. Ca2+ image analysis showed that Ca2+ is stored in vesicular structures and released into the cytoplasm within 60 s after temperature stimulation. Multiple signaling pathways are activated after the release of Ca2+ from vesicles, and cAMP is a candidate second messenger with a crucial role in the process of temperature-induced encystment. Further studies are needed to clarify the mechanism underlying the sensing of temperature and release of Ca2+ from vesicles.

Electrocatalytic hydrogen evolution reaction (HER) is promising to achieve conversion of renewable electricity into storable chemical energy. For practical installation of such technology, it is important to develop active and stable electrocatalysts without relying on rare metal elements. Recently, some metal-free conductive organic polymers such as poly-dopamine (PDA) and poly-guanine (PG) have been found to exhibit stably high catalytic activity towards HER1-3. Also, we have achieved polymerization of neutral red (NR) dye, which is chemically analogous to aniline and bears amino groups at a high density. Oxidative chemical vapor deposition (oCVD) or electrodepolymerization deposition (EPD) were the techniques to achieve formation of PNR. PNR exhibited a good catalytic activity for CO2 reduction reaction (CO2RR), although the one prepared by oCVD was about twice as active as that by EPD. Structural disordering of the oCVD sample was supposed to contribute to the catalysis. It is likely that there is an optimum for the balance between conductivity and the density of hydrogen bonding sites. In this study, we have studied electrochemical co-polymerization of NR and aniline to find the optimum design of the catalyst. Electro-polymerization of poly-aniline (PANI), PNR or co-polymer PANI-PNR was carried out at an F-doped tin oxide (FTO) coated conductive glass (Asahi-DU) or a carbon felt (CF, Jing Long Te Tan) substrate by potential cycling between -0.2 and +1.0V vs. Ag/AgCl in aqueous solutions containing ANI, NR or their mixtures at appropriate ratios at a total monomer concentration of 50 mM and 0.1 M H2SO4 for 50 (FTO) or 20 cycles (CF) under N2. Linear sweep voltammetry (LSV) was performed on polymer coated CF electrodes in a 0.5 M H2SO4 under N2 for evaluation of HER catalysis. PANI appeared dark green, PNR red, whereas PANI-PNR was black. These color differences already speak for successful loading of NR into PANI to achieve PANI-PNR copolymer. Cyclic voltammograms (CVs) during EPD of PANI and PNR show the characteristic redox peaks3 (Fig. 1 a, b). While redox peaks of PANI continue to grow, the reversible redox peaks of NR almost stay the same, since formation of cation radical of NR under the present acidic condition is inefficient.3 When ANI and NR are blended, however, CV that differ from those for homopolymers of PANI and PNR is obtained (Fig. 1c). Although this CV is not the exact superimpose of the two for PANI and PNR, it suggests the presence of NR in the film and its contribution to the redox behavior. HER current in LSV almost remains the same when CF is coated with PANI, indicating its disability of electrocatalysis (Fig. 1d). Although PANI should be the most conductive among the polymers we tested here, PANI does not possess hydrogen bonding amino groups. PNR only showed moderate catalysis partly due to the small film thickness we could achieve under the current preparation condition. The PANI-PNR copolymer indeed exhibited very high catalytic activity to reduce the overvoltage as small as 250 mV. It is likely that NR provides hydrogen bonding catalytic centers while PANI assures a high conductivity. Thus, a superior catalysis has been achieved by the co-polymer strategy than using the homopolymers. The optimal compositional balance between PANI and PNR should be found by further experimental elaboration. References: Coskun et al., Mater., 2020, 1902177. Coskun et al., Mater. interfaces, 2019, 1901364. Xin Huang et al., 237th ECS meeting abstract, 2019, 135704. Figure 1

１． Intention Concentration of carbon dioxide (CO2) in the atmosphere has steadily increased since industrial revolution. Despite the recent significant cost reduction of renewable electricity by solar and wind, their intermittency hinders the total shift to renewable energy. It is urgently needed to develop technologies for fast conversion of electrical energy into storable chemical energy by electrolysis, e.g., by water splitting and CO2 reduction. Stable and high-performance electrocatalysts are essential but must be developed without depending on precious metals for the real use and sustainability of the technology. Recently, we have demonstrated high and stable electrocatalytic properties of conductive organic polymers, such as polydopamine (PDA) and polyguanine (PGA) for hydrogen evolution reaction (HER) and CO2 reduction reaction (CO2RR)1,2). Hydrogen bonding N and O atoms introduced to these polymers are expected to stabilize the reaction intermediates for their high catalytic activities. In this study, a phenazine dye, neutral red (NR) was employed as the monomer to obtain a metal-free catalyst. NR bears many amino functions to make it electropolymerizable just like poly-aniline (electropolymerization deposition, to be called EPD). Also, oxidative chemical vapor deposition (oCVD) was employed to obtain PNR. Synthesis, characterization and comparison of the catalytic activities of PNR by EPD and oCVD are discussed. ２． Experiment EPD of PNR onto carbon felt (CF) was carried out by cycling potential between -1 and +1 V vs. Ag/AgCl for 100 cycles in an aqueous solution containing 0.2 mmol/L NR and 0.5 mol/L KNO3 (pH 5) at 50 mV/s. oCVD of PNR was performed in a three-zone quartz tube furnace under N2 flow, while setting the temperature for NR, sulfuric acid and CF at 375, 220 and 100ºC, respectively, for 240 min. PNR-modified as well as bare CF electrodes were measured under N2 and CO2 in a 1 M KNO3 (pH 7) for their catalytic activities for HER and CO2RR. ３． Result While bare carbon felt (CF) electrode does not show any catalytic activity towards CO2RR, showing about -3 mA cm-2 current at –1 V vs. Ag/AgCl, supposedly dominated by that for HER, the PNR coated CFs show enhanced current (Fig. 1a). That by EPD gives about -5 and -6 mA under N2 and CO2, respectively, indicating its moderate catalytic activity for HER and CO2RR. PNR prepared by oCVD, on the other hand, gives -6 and -12 mA, to demonstrate its superior activity, especially for CO2RR. Chronoamperogram measured during long term electrolysis for 17 h at the oCVD PNR electrode indicates reasonable stability of the catalysis (Fig 1b). These results already nicely confirm catalytic activity of PNR for its conductivity and hydrogen-bonding ability. H. Coskun et al., Sci. Adv. 3, e1700686 (2017). H. Coskun et al., Adv. Mater. Interf. 10, 1901364 (2019). Figure 1

1. Introduction Hydrogen is a promising energy carrier, but is currently produced by steam reforming of fossil fuels to discharge CO2. Water splitting by electricity from renewable resources is an ideal solution. However, expensive and rare metals such as Pt and Ru are needed as electrocatalysts for their high activity and durability. We have recently found that metal-free organic conductive polymer made by polymerization of guanine (PG) exhibits a high catalytic activity for hydrogen evolution reaction (HER) close to that of Pt.1,2,3 Hydrogen bonding sites in PG are supposed to stabilize the reaction intermediates. It is also interesting that a nucleic acid as one of the key components of DNA has such properties for HER catalysis. In this work, we have explored other nucleic acids, namely, adenine, cytosine and thymine for their capabilities of polymerization by oxidative chemical vapor deposition (oCVD) and HER activities. 2. Experimental oCVD was carried out in a 3-zone heating quartz tubular furnace, in which 0.5 g of monomer (set to 300~360°C depending on melting points), oxidant (mixture of 0.5 mL sulfuric acid and 0.5 g sodium sulfate, 360°C) and carbon felt (CF) substrate (1.5 cm × 2.5 cm, Jing Long Te Tan, 360°C) were put under N2 stream (3 L/min). The deposition was maintained for 30 minutes after the set temperatures were reached and then allowed to cool down. FT-IR spectra were measured to check formation of conductive polymers. Linear sweep voltammetry (LSV) was performed at 10 mV/s on the polymer coated CF electrodes in a 0.1 M sulfuric acid under N2 to evaluate overvoltage for hydrogen evolution reaction (HER) at 10 mA/cm2. 3. Results and Discussion A black layer was formed by oCVD of adenine. Its FT-IR spectrum exhibited broad peaks around 3000 cm-1, indicative of hydrogen bonds, as well as several strong peaks below 1000 cm-1, which shows presence of free charge carriers to evoke infrared-activated vibration (IRAV). Since similar features were observed in the FT-IR of PG,2 formation of conductive poly-adenine (PA) is reasonably expected. While oCVD of cytosine also yielded similar black film, suggesting formation of PC, that of thymine did not afford any product on the substrate, despite several trials to change temperatures and other deposition conditions. The difference can be reasoned as adenine and cytosine bear cross-linkable amino groups, whereas thymine does not have one. Preliminary electrochemical study revealed an overvoltage of CA. 700mV, far larger than that of PG (290 mV).2 While PG has a hydrogen donating -NH group and a hydrogen accepting ketone group in α-position, PA does have an -NH group but not a ketone. Such difference in the structure of hydrogen bonding site is a possible reason for the large difference of the catalytic activity. Further studies about the HER electrocatalysis are under investigation. References: Coskun et al., Sci. Adv. 2017, 3, e1700686. Coskun et al., Adv. Mater. interfaces, 2019, 1901364. Coskun et al., Adv. Mater. 2020, 1902177.

Concentration of carbon dioxide (CO2) in the atmosphere has steadily increased since industrial revolution. Despite the recent significant cost reduction of renewable electricity by solar and wind, their intermittency hinders the total shift to renewable energy. It is urgently needed to develop technologies for fast conversion of electrical energy into storable chemical energy by electrolysis, e.g., by water splitting and CO2 reduction. Stable and high-performance electrocatalysts are essential but must be developed without depending on precious metals for the real use and sustainability of the technology. Recently, we have demonstrated high and stable electrocatalytic properties of conductive organic polymers, such as polydopamine (PDA) and polyguanine (PGA) for hydrogen evolution reaction (HER) and CO2 reduction reaction (CO2RR)1,2). Hydrogen bonding N and O atoms introduced to these polymers are expected to stabilize the reaction intermediates for their high catalytic activities. In this study, a phenazine dye, neutral red (NR) was employed as the monomer to obtain a metal-free catalyst. NR bears many amino functions to make it electropolymerizable just like poly-aniline (electropolymerization deposition, to be called EPD). Also, oxidative chemical vapor deposition (oCVD) was employed to obtain PNR. Synthesis, characterization and comparison of the catalytic activities of PNR by EPD and oCVD are discussed. EPD of PNR onto carbon felt (CF) was carried out by cycling potential between -1 and +1 V vs. Ag/AgCl for 100 cycles in an aqueous solution containing 0.2 mmol/L NR and 0.5 mol/L KNO3 (pH 5) at 50 mV/s. oCVD of PNR was performed in a three-zone quartz tube furnace under N2 flow, while setting the temperature for NR, sulfuric acid and CF at 375, 220 and 100ºC, respectively, for 240 min. PNR-modified as well as bare CF electrodes were measured under N2 and CO2 in a 1 M KNO3 (pH 7) for their catalytic activities for HER and CO2RR. While bare carbon felt (CF) electrode does not show any catalytic activity towards CO2RR, showing about -3 mA cm-2 current at –1 V vs. Ag/AgCl, supposedly dominated by that for HER, the PNR coated CFs show enhanced current (Fig. 1a). That by EPD gives about -5 and -6 mA under N2 and CO2, respectively, indicating its moderate catalytic activity for HER and CO2RR. PNR prepared by oCVD, on the other hand, gives -6 and -12 mA, to demonstrate its superior activity, especially for CO2RR. Chronoamperogram measured during long term electrolysis for 17 h at the oCVD PNR electrode indicates reasonable stability of the catalysis (Fig 1b). These results already nicely confirm catalytic activity of PNR for its conductivity and hydrogen-bonding ability. References: 1. H. Coskun et al., Sci. Adv., 2017, 3, e1700686. 2. H. Coskun et al., Adv. Mater. Interf., 2019, 10, 1901364. Figure 1

Among various metal oxides previously tested, Co3O4 is known to be one of the best catalysts for oxygen evolution reaction (OER). In this study, doping of Co ions into nanocrystals of zinc oxide (ZnO) has been achieved by microwave (MW) assisted hydrothermal reaction to form catalytic surface sites for OER combined with highly conductive and stable ZnO for flexible catalyst design and potential enhancement of the catalytic activity. MW-assisted hydrothermal reaction has successfully achieved synthesis of Co-doped ZnO nanocrystals at a low reaction temperature of 160ºC and in a short reaction time of 30 min. Partial replacement of 4-coordinated Zn(II) ions of ZnO with Co(II) ions up to about 10at% has been suggested from evaluation of the products by UV-Vis absorption spectra, morphological observations and X-ray diffraction. The higher addition of Co resulted in its phase-separated precipitation as Co(OH)2. While mesoporous electrode processed from ZnO nanocrystals was totally inactive for water oxidation, that of Co-doped ZnO exhibited a good catalytic activity to achieve about 1 mA cm-2 current of OER with an overvoltage of 0.545 V in a neutral aqueous KCl solution, which in fact was far superior to a Co3O4 electrode known to suffer from its limited conductivity. The doped Co ions are only expected to act as reaction centers for charge transfer on the very surface in contact with the electrolyte, while ZnO acts as a highly conductive and chemically stable host matrix to support the catalyst.

Electrocatalytic hydrogen evolution reaction (HER) and carbon dioxide reduction reaction (CO2RR) are the key reactions for conversion of renewable electricity into storable chemical energies. It is crucially important to develop active and stable electrocatalysts without relying on rare metal elements for sustainable energy systems. Recently, some metal-free conductive organic polymers such as polydopamine (PDA) and poly guanine (PGA) synthesized by oxidative chemical vapor deposition (oCVD) have been found to exhibit high catalytic activity and durability for HER and CO2RR1,2. In addition to their conductivity of the π-conjugated system of the main chain, these polymers contain heteroatoms such as N and O at high densities, which are believed to act as hydrogen bonding sites for stabilization of reaction intermediates. However, their exact structures and relationship to the catalytic activities are not fully grasped. In this study, we employ electro-polymerization as the mean to obtain catalytic polymers. Taking polyaniline (PANI) as the host, hydrogen bonding monomers such as dopamine (DA), guanine (GA) and neutral red (NR) are to be introduced to obtain co-polymers with controlled structure and density of the hydrogen bonding sites. Comparison of their electrocatalytic activity to those of the respective homo-polymers should reveal the effective catalytic sites and its product selectivity, which should result in optimal design of the catalyst. Electro-polymerization of PANI and PNR was carried out at an ITO glass substrate in an aqueous solution containing 50 mM ANI or NR and 0.1 M H2SO4 during 50 times potential cycling between -0.5 and +0.6 V vs. Ag/AgCl under the N2. Copolymers were obtained by mixing the monomers at appropriate ratios. The films were characterized by FT-IR spectra. PANI, PNR and their copolymer appeared dark green, dark red and black, respectively. While CVs during electropolymerization of PANI continue to increase the redox peaks of PANI as typically expected, those for PNR show decrease of anodic current suggesting inactiveness of PNR for its redox (Figs. 1 a, b). When they are mixed together, a new redox peak in between those from PANI and another irreversible anodic peak close to +0.9 V appear, which indicate loading of NR in redox active form into PANI (Fig. 1c). The FTIR spectrum of the copolymer showed significant difference from the homo-polymers of PANI and PNR with intense absorption peaks between 800 and 1600 cm-1 (Fig. 1d). These peaks arise from infrared-activated vibrations (IRAV) due to the presence of polaron in the main chain, thus are indicative of its conductive nature. These results suggest improvement of conductivity by heterogeneity in copolymers. Its relevance to the catalytic property and optimal density of hydrogen bonding sites are to be further investigated. References: 1. Coskun et al., Adv. 2017, 3, e1700686. 2. Coskun et al., adv mater interfaces, 2019, 1901364. Figure 1

Functional particles such as TiO2 and Pt/C are often fixed on a flat substrate for practical uses. rotating ring disk electrode (RRDE) technique, in which Pt/C nanoparticles were dispersed on a glassy-carbon (GC) disk electrode, is known as a method capable of evaluating a catalyst activity. The technique was often applied to the evaluation of oxygen reduction catalysts used in fuel cells or metal-air batteries, because the reaction intermediates such as hydrogen peroxide can be detected by the ring electrode. However, the accuracy of the technique was significantly affected by the dispersivity of the catalyst particles on the electrode. Thus, the catalysts on the disk electrode are required to be uniformly dispersed and many researchers have sought the best dispersion method. Although microscope photographic images were used for the estimation of dispersivity on the electrode, no quantitative analyses were performed by using the images. In this study, we have developed a program called “Roughness Analyzer” which can quantitatively analyze the dispersiveness of particles on a flat substrate. This software can load a three dimensional data of particles fixed on a substrate measured by a surface roughness meter (SV-C4500 CNC, Mitutoyo) and display a 2D contour map of the loaded data. It should be noted that, the height of each point is expressed by the brightness of each dot. If necessary, a user can change the range of height represented by the brightness and the number of level. This software is equipped with an auxiliary function to estimate only a substrate surface from a three-dimensional data of the particles fixed on a substrate. This function can automatically determine the points of each cross-section of the 2D contour map that is likely to be surface of the substrate itself, and curves connecting these points was obtained by a spline interpolation method. Thus, only particle-derived height data are calculated by subtracting the height of only the substrate surface data from that of experimental raw data. Analytical functions are “Cluster Analysis” and “Distribution Analysis.” The Cluster Analysis can detect each secondary particle agglomerated on the substrate from the height data. Each secondary particle is filled with a different color and the area, the volume, and the average height of each particle are calculated respectively. The Distribution Analysis can divide the substrate surface in any number from the center of the substrate surface in a radial direction and an angular direction. Further, it can automatically calculate the area, the volume and the percentages of area occupancy of particles in each section. For example, the dispersiveness of a modified GC electrode was evaluated by the software. The electrode was prepared as follows: A 2.0 mg of Pt/MWCNTs was suspended in 1 mL of 0.1 wt% Nafion-EtOH by ultrasonication for 10 min. Then, 10 μL of the suspension was cast onto a glassy-carbon disk (6 mm φ, 0.283 cm2) – Pt ring electrode (Nikko Keisoku) and dried for 1 h at 60°C by using an infrared lamp. Fig. 1 shows the percentage of the area occupancy for the secondary particles in each section. Each cumulative bar represents the percentage of area occupancy in the same radial range, thus, it means good dispersivity of the particles when each cumulative bar has similar height, namely, the standard deviation of the heights is small. Moreover, each element in each cumulative bar means the percentage of area occupancy for the particles at a different angular direction in the same radial range. The desirable dispersivity can be achieved when the standard deviation of the height of the bars is small. However, the small standard deviations are not a sufficient condition for good dispersivity. Criteria for dispersivity are the average height of the particles as well as the standard deviations. Figure 1

A hydrogen society are one of the solution to alleviate the current global warming. However, since the energy density of hydrogen is low in the gas state, hydrogen must be transported under high pressure or liquid state, which causes energy loss. Ammonia is a promising hydrogen carrier because of its low production cost and ease in liquefaction and transport. A low temperature direct ammonia type fuel cell (DAmFC) is a device for directly extracting energy from ammonia. However, even Pt and Ir do not have enough catalytic activity for ammonia oxidation at low temperatures, which is disturbing practical application. The reason is that an inert surface poisoning by strongly adsorbed nitrogen (Nad) takes place competitively with a reaction generating nitrogen molecules. We investigated the desorption process of Nad on an Ir disk electrode and multiwalled carbon nanotube supported Ir nanoparticles (Ir/MWCNT) by normal pulse voltammetry (NPV). The purpose of this study is to analyze the desorption process of Nad generated during ammonia oxidation on Pt/C. To prepare catalyst modified electrode, 2 mg of 20 % Pt/XC-72 (E-TEK) was dispersed in 0.1 wt%Nafion-2-PrOH solution, and 10 μL of the dispersion was cast on a glassy carbon disk electrode (6 mm) and dried by hot wind. A three-electrode cell configuration was adopted using the modified electrode as the working electrode, a Pt wire as the counter electrode and RHE as the reference electrode. Electrochemical measurements were performed in 0.1 M NH3– 0.1 M KOH aqueous solution in nitrogen atmosphere. All potentials shown in this abstract are quoted with respect to the RHE. To analyze the desorption process of Nad, a waveform used in the NPV was shown in Fig. 1. First, Nad was generated by applying a potential step to 0.6 V, where ammonia oxidation occurs, for 180 s to generate Nad. After that, Nad was attempted to be desorbed by applying potential step to E recover [V] (0.4 V – 0.1 V) for a certain time (t recover, 1 s – 180 s). Finally, ammonia oxidation current with non-Faradaic current was obtained by reapplying potential step to 0.6 V. The ammonia oxidation current was determined by subtracting the current value considering the change in solution resistance and charging capacity in 0.1 M KOH. Assuming that desorption process consists of two independent pseudo first-order reactions, the oxidation current is expressed by the following equation: i (0.6V,0.5s)= I max Γ [p{1-exp(-k1 t recover) }+ (1-p){1-exp(-k 2 t recover)}] (1) where I max[μAcm-2 ECSA] is the maximum ammonia oxidation current normalized by electrochemically active surface area (ECSA), Γ is the relative coverage of the ammonia, p is the rate of the fast reaction, and k 1 [s-1] and k 2 [s-1] are the pseudo-first order reaction rate constants, and each parameter was determined by the nonlinear least square method. Fig. 1 shows the t recover dependence of the ammonia oxidation current after applying various E recover. The current reached almost a plateau after 60 s of applying E recover, suggesting that the Nad dissociation reaction reached equilibrium at the potentials. The current increased with decreasing E recover. Nad dissociation was promoted at the hydrogen adsorption/desorption potential region. Thus, it is predicted that hydrogen atoms adsorbed on the Pt atoms react with Nad, followed by desorption of N x H y . Figure 1

Noda epileptic rat (NER) is a genetic rat model of epilepsy that exhibit spontaneous generalized tonic-clonic (GTC) seizures with paroxysmal discharges. We analyzed the regional expression of Fos-like immunoreactivity (Fos-IR) following GTC seizures in NER to clarify the brain regions involved in the seizure generation. GTC seizures in NER elicited a marked increase in Fos expression in the piriform cortex, perirhinal-entorhinal cortex, insular cortex and other cortices including the motor cortex. In the limbic regions, Fos-IR was highest in the amygdalar nuclei (e.g., basomedial amygdaloid nucleus), followed by the cingulate cortex and hippocampus (i.e., dentate gyrus and CA3). As compared to the above forebrain regions, NER either with or without GTC seizures exhibited only marginal Fos expression in the basal ganglia (e.g., accumbens, striatum and globus pallidus), diencephalon (e.g., thalamus and hypothalamus) and lower brain stem structures (e.g., pons-medulla oblongata). These results suggest that GTC seizures in NER are of forebrain origin and are evoked primarily by activation of the limbic and/or cortical seizure circuits.

Background: The inwardly rectifying potassium channel subunit Kir4.1 is specifically expressed in astrocytes, which mediates spatial K+ buffering and is implicated in the pathogenesis of convulsive epileptic disorders (ie, generalized tonic-clonic (GTC) and temporal lobe seizures). Objectives: This study aimed to explore the pathophysiological role of Kir4.1 channels in modulating absence seizure incidence, using a spontaneously epileptic animal model. Materials and Methods: Groggy rats, a rat model of human absence seizures, and Slc:Wistar (control) rats, were used in this study. Cortical and hippocampal EEG were recorded to confirm the seizure incidence in Groggy rats. The expression levels of Kir subunits (ie, Kir4.1, Kir5.1 and Kir2.1) in ten brain regions were analyzed by Western blotting. Results: Groggy rats showed a high incidence (ca. 350 seconds total duration/15 minutes observation period) of absence-like seizures, which were characterized by a sudden immobile posture and synchronously-associated spike and wave discharges. However, Western blot analysis revealed that Kir4.1 expression in Groggy rats was not significantly different from that of control rats in any of the brain regions examined (eg, cerebral cortex, striatum, hippocampus, diencephalon, midbrain, pons/medulla oblongata and cerebellum). In addition, expressional levels of Kir5.1 and Kir2.1, which are also expressed in astrocytes, were unaltered in Groggy rats. Conclusions: The present results suggest that unlike GTC and temporal lobe seizures, pathophysiological alterations (eg, dysfunction and/or expressional changes) of Kir4.1 are not linked to non-convulsive absence seizures.

The inwardly rectifying potassium (Kir) channel Kir4.1 in brain astrocytes mediates spatial K(+) buffering and regulates neural activities. Recent studies have shown that loss-of-function mutations in the human gene KCNJ10 encoding Kir4.1 cause epileptic seizures, suggesting a close relationship between the Kir4.1 channel function and epileptogenesis. Here, we performed expressional analysis of Kir4.1 in a pilocarpine-induced rat model of temporal lobe epilepsy (TLE) to explore the role of Kir4.1 channels in modifying TLE epileptogenesis. Treatment of rats with pilocarpine (350 mg/kg, i.p.) induced acute status epilepticus, which subsequently caused spontaneous seizures 7-8 weeks after the pilocarpine treatment. Western blot analysis revealed that TLE rats (interictal condition) showed significantly higher levels of Kir4.1 than the control animals in the cerebral cortex, striatum, and hypothalamus. However, the expression of other Kir subunits, Kir5.1 and Kir2.1, remained unaltered. Immunohistochemical analysis illustrated that Kir4.1-immunoreactivity-positive astrocytes in the pilocarpine-induced TLE model were markedly increased in most of the brain regions examined, concomitant with an increase in the number of glial fibrillary acidic protein (GFAP)-positive astrocytes. In addition, Kir4.1 expression ratios relative to the number of astrocytes (Kir4.1-positive cells/GFAP-positive cells) were region-specifically elevated in the amygdala (i.e., medial and cortical amygdaloid nuclei) and sensory cortex. The present study demonstrated for the first time that the expression of astrocytic Kir4.1 channels was elevated in a pilocarpine-induced TLE model, especially in the amygdala, suggesting that astrocytic Kir4.1 channels play a role in modifying TLE epileptogenesis, possibly by acting as an inhibitory compensatory mechanism.

Although ammonia is expected as the next generation of energy medium, even platinum, which is a relatively active ammonia oxidation (AO) catalyst, have an insufficient performance for direct ammonia fuel cells (DAmFCs) operating below 100°C. Highly active AO catalysts at low temperatures needs to be developed in order to use ammonia as a fuel for DAmFCs. AO mechanism on platinum is reported as follows: After NH3 is adsorbed on the platinum surface, the AO proceeds via two competitive paths. One is the formation of hydrazine analogues, followed by the oxidation of the analogues to release N2 molecules. The other is the oxidation of an ammonia molecule to form nitrogen atoms adsorbed onto the surface of platinum (Nads) known as poisoning species. However, after the surface of the platinum is covered with Nads, the elimination process of Nads is not known. In this study, the elimination process was studied by a normal pulse voltammetry. 33.6 wt% Pt/MWCNT (average particle size: 5.57 ± 0.11 nm) catalyst was synthesized by a microwave polyol method. A 2 mg of Pt/MWCNT was suspended in 1 mL of Pt/MWCNT-0.1 wt% Nafion-MeOH by ultrasonication for 10 min. 10 μL of the suspension was cast onto a glassy carbon (GC) disk electrode (6 mm φ), followed by drying for 1 h in air. Electrochemical measurements were performed with a conventional three electrode system equipped with the modified GC electrode, an Au wire counter electrode and a reversible hydrogen electrode (RHE) in 0.1 M KOH or 0.1 M NH3-0.1 M KOH. The normal pulse voltammetry was performed as follows: After the Nads was formed by applying 0.6 V for 180 s, E recover (V) was applied for various times (1 s，5 s，10 s，20 s，60 s, and 180 s) to eliminate Nads. Then, the AO current at 0.6 V after 1 s was used as an indicator for the amount of Nads poisoning. Fig. 1 shows the dependence of AO current at 0.6 V after 1 s on recovery potential. The AO current gradually recovered by maintaining the potential below 0.4 V vs. RHE, indicating that the adsorbed N atoms were eliminated from the catalyst surface. It took a few minutes to recover the AO current. In addition, the decrease in potential accelerated the recovery of the AO current, especially below 0.3 V vs. RHE. The final percentage of the recovery increased with a decrease in the potential. The recovery rates below 0.25 V called hydrogen adsorption/desorption region increased with decreasing potential, probably due to the reduction of Nads. The time dependence of the recovery rate was analyzed by the sum of two exponentials, suggesting that the fast and slow reactions exists in the recovery process. Figure 1

When the activity of a catalyst was estimated by a rotating ring disk electrode (RRDE) method, the modified glassy carbon (GC) electrode was generally fabricated by casting catalyst suspension prepared by various methods, followed by drying under various conditions. There are many preparation methods for catalyst suspension. And it is known that the dispersivity of the catalyst on the GC electrode, which affects collection efficiency of H2O2as well as current density, depends on the above methods and conditions. Since an optimum method and condition often varies with the kinds of catalysts, researchers have to find them. However, it is difficult to evaluate the dispersivity on the electrode and reproducibility quantitatively. In this study, the dispersivity of multi wall carbon nanotube supported Pt catalyst (Pt/MWCNT) on the modified electrode prepared by various methods was estimated by digitizing height data of the electrode using a laser surface roughness meter. 30 wt% Pt/MWCNT (Pt particle size: 4.26 ± 0.09 nm) catalyst was synthesized by a microwave polyol process. 2 mg/mL of 30 wt% Pt/MWCNT-0.1 wt% various alcohol (MeOH, EtOH, and 2-PrOH) suspensions were prepared by ultrasonication for 10 min. 10 μL of the suspensions cast on a GC electrode, and the electrode allowed to dry by three method: 1) in air for 1 h (abbreviated as Air), 2) in saturated ethanol vapor pressure for 1 h (EV), and 3) in air with infrared irradiation for 10 min at 60 °C (IR). The samples were named as [solvent] – [drying method]. The modified electrodes were observed with a digital microscope (MSP-3080, PANRICO). And the surface height data of the modified electrodes were digitized with a laser surface roughness meter (SV-C4500 CNC, Mitutoyo), and the data were analyzed by a software "Roughness Analyzer" developed by our laboratory. The software detects secondary particles of the catalyst (clusters) on the electrode and the user can obtain the volumes, the average height, and the area of the clusters as well as the distribution of the catalysts from the center of the electrode. Fig. 1 (a) shows cumulative cluster volume distribution for MeOH–Air, 2-PrOH-Air and EtOH–EV. The electrode surface prepared by the EtOH-EV method had the clusters up to 1.9×10-3 mm3, whereas those prepared by MeOH-Air and EtOH-EV had the clusters up to 6.7×10-4 mm3 and 1.9×10-3 mm3, respectively, suggesting that the EtOH-EV method tend to be aggregated to produce large secondary particles. Fig. 1 (b) shows the average cluster heights of the samples. The standard deviation of the average cluster height for 2-PrOH-Air was the smallest of the three methods, indicating that the 2-PrOH-Air method is the most reproducible casting method of the three methods. Some quantification methods will be reported in the meeting. Figure 1

A novel de-centralized dynamic inter-cell interference coordination (ICIC) method, which can change cell-edge bands dynamically by using an X2 interface and can be applied to current downlink long-term evolution (LTE) systems, is proposed. This dynamic ICIC method can autonomously optimize fractional frequency reuse (FFR) parameters and thus increase throughput. In addition, it works well even in the presence of control delays in time-variable environments. Static and dynamic system-level simulation (SLS) demonstrated that the throughput achieved by the proposed method is superior to that of conventional FFR methods.