bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhanced Photocatalytic H2 Evolution over P-Doped g-C3N4 with Aromatic Rings Composites
Authors: Kobayashi Yuya , Katsumata Hideyuki , Tateishi Ikki , Furukawa Mai , Kaneco Satoshi 
Published: December 2020

Introduction

Photocatalytic water splitting is a promising strategy to convert solar energy into chemical energy [1]. In recent years, graphitic carbon nitride (g-CN) has attracted attention due to its desirable properties, including nontoxicity, low cost, thermal stability and visible-light activity [2]. However, the photocatalytic activity of g-CN is limited by the high recombination rate of photoinduced electron-hole pairs [3,4]. In this study, phosphorus doped g-CN with aromatic rings (A/P-CN) composites were prepared. Those composites were evaluated by the photocatalytic hydrogen production under visible light (λ ≥ 420 nm) and characterized by some instrumental analysis.

Results and Discussion

In summary, A/P-CN composite photocatalysts with enhanced photocatalytic H2 evolution performance were successfully synthesized by the calcination of the mixture of urea, 1,3,5-hydroxy benzene and Cl6N3P3. The sample with optimal loading amounts of aromatic rings and phosphorus showed the highest H2 production rate of 550 μmol h-1 g-1, which was about 4.5 times higher than that of pristine g-CN (120 μmol h-1 g-1) (Figure 1). Thus, aromatic rings and phosphorus doped composites push the g-C3N4-based materials forward as the promising visible-light-active photocatalysts with high efficiency in the energy applications.

References

[1] S. Chen, T. Takata, K. Domen, Nat. Rev. Mater.
2017, 2, 17050.
[2] Y. Wang, X. Wang and M. Antonietti, Angew. Chem., Int. Ed.
2012, 51, 68.
[3] G. Liu, P. Niu, C. Sun, S. C. Smith, Z. Chen, G. Lu and H. Cheng, J. Am. Chem. Soc.
2010, 132, 11642.
[4] L. S. Dake, J. Vac. Sci. Technol. A
1989, 7, 1634.

Figure 1
Electrochemical Decolorizaton of Dye in Solution with Modified Ti/α-PbO2/β-PbO2 Mesh Electrode
Authors: Yanagi Genta , Furukawa Mai , Tateishi Ikki , Katsumata Hideyuki , Kaneco Satoshi 
Published: December 2020

The synthetic dyes with high stable aromatic structures severely impair watery environments, due to their low biodegradability and deep color-staining. Furthermore, dye pollution would inhibit aquatic plants’ photosynthsis process, decrease the concentration of dissolved oxygen, and contain substances that are toxic to the human body.
The electrochemical oxidation is an attractive advanced wastewater oxidation process, which has been applied in toxic or refractory wastewater treatment, owing to its simplicity, easy operation, environmental compatibility, mild condition and high efficiency. Their degradation performance depends strongly on the selected anode materials. Thus, it is necessary to develop excellent anode materials with high stability and electrocatalytic activity.
Recently, various anode materials have been fabricated and studied. PbO2 electrodes could be regarded as important metal oxide anodes for pollutant remediation, because of their high chemical stability, easy preparation, high oxygen evolution overpotential, good conductivity, high catalytic activity, cheap and available. However, PbO2 film can peel off easily for its relatively large internal stress. The phenomena cause the leakage of Pb ions and releasing into the solution. Therefore, the improvements of stability and electrocatalytic performance for PbO2 electrodes are significant for the application. Recently, many studies have been investigated for the enhancement of electrode performance, such as the modification of substrate, the introduction of interlayers and the doping of metal ions or particles [1-3].
In the previous study, the electrochemical decolorizaton of Methylene blue in solution with Ti/α-PbO2/β-PbO2 Sheet electrode has been investigate. In the present work, Ti/α-PbO2/β-PbO2 Mesh electrode was modifeid by the doping of metal, and have been applied into the electrochemical remediation of Methylene blue in the solution.
References
[1] Y. Yao, B. Ren, Y. Yang, C. Huang, M. Li., J. Hazard. Mater. 2019, 361, 141.
[2] Y. Xia, Q. Dai., J. Hazard. Mater. 2018, 205, 215.
[3] X. Wang, Q. Wu, H. Ma, C. Ma, Z. Yu, Y. Fu, X. Dong. J. Sol. Energy Mater. Sol. Cells, 2019, 191, 381.

Figure 1
(Invited) Printed Built-in Power Sources with Dimensional Conformability
Authors: Lee Sang-Young 
Published: December 2020

The ongoing surge in demand for flexible/wearable electronics, self-powered systems, soft robotics, and Internet of Things (IoT) has inspired the relentless pursuit of form factor-free, high-performance power sources that can be monolithically and seamlessly integrated with various electronics. To reach this challenging goal, a new class of advanced power sources with various form factors that are different from existing commercial ones are needed. From the viewpoint of power source design and architecture, traditional cell materials and fabrication have resulted in power sources that feature a lack of variety in form factors and flexibility. In specific, most of the current power sources are manufactured by winding or stacking of slurry-casted electrode sheets and separator membranes, followed by the injection of liquid electrolytes inside a fixed form of canisters or pouch packaging substances; these methods impose stringent restrictions on the unitization of power sources with electronic devices. Printed power sources have recently garnered considerable attention as a fresh and game-changing approach due to their design diversity, shape/performance compatibility with electronic devices, and scalable/low-cost processability. Printed power sources based on high-fidelity printing techniques and rationally designed material chemistry are fabricated directly on complex-shaped objects, thereby enabling monolithic integration and electrochemical coupling with target devices that lie far beyond those achievable with conventional power source technologies.
Here, this talk introduces form factor-free, printed built-in power sources, with particular attention to their dimensional conformability and performance compatibility with newly emerging complex-structured electronic devices. A key-enabling technology for the printed power sources is the design of battery inks (specifically, electrode and electrolyte inks), with a focus on their rheology and electrochemistry. Our research interests are directed to discussing effects of the battery inks on printing processability, microstructure (focusing on bicontinuous ion/electron transport channels) and electrochemical performance of the resultant printed power sources. We envision that the printed power sources open a new avenue towards form factor-free/monolithic integrated power sources with object-tailored design versatility and dimensional conformability.

References

[1] Kwon-Hyoung Lee, David B. Ahn, Jung-Hui Kim, Ju-Won Lee, Sang-Young Lee*,
Matter
, 2020, 345.
[2] Kwon-Hyoung Lee, Seong-Sun Lee, David B. Ahn, Jaehyun Lee, Doyouong Byun, Sang-Young Lee*,
Sci. Adv.
, 2020, eaaz1692.
[3] Jihun Park, David B. Ahn, Joohee Kim, Eunkyung Cha, Byeong-Soo Bae, Sang-Young Lee*, Jang-Ung Park*,
Sci. Adv.
, 2019, eaay0764.
[4] Keun-Ho Choi, David B. Ahn and Sang-Young Lee*,
ACS Energy Lett.

2018, 3, 220.
[5] Keun-Ho Choi, JongTae Yoo, Chang Kee Lee and Sang-Young Lee*,
Energy & Environ. Sci.

2016, 9, 2812.

Figure 1
(Invited) Photoluminescent ZnO Thin Films By Photochemical Gel Conversion Under VUV Irradiation
Authors: Sun Lina , Uda Kyota , Yoshida Tsukasa , Suzuri Yoshiyuki 
Published: December 2020

Zinc oxide (ZnO), as a wide band gap (3.37 eV) semiconductor, are useful materials for wide range of applications in thin-film transistor (TFT), photovoltaics, photocatalysts, sensors, and so on. Large exciton binding energy (60 meV) at room temperature (RT) makes ZnO a promising luminescent material especially in optoelectronic devices such as UV lasers and light emitting diodes (LED). Among them, ZnO nanocrystals (quantum dots) has attracted increasing attention because their optical properties can be tuned by varying the crystal size. However, its nanoscale crystallites tend to aggregate to undergo Ostwald ripening due to their high surface energy. To stabilize them, surface modification are usually necessary. At the same time, the whole processes for nanocrystal synthesis and film fabrication become complicated.
Here, we report a simple novel photochemical gel conversion approach for one-step preparation of ZnO thin films with an average nanocrystals in about 2-3 nm size (inset in Fig. 1a), by employing vacuum ultraviolet (VUV) light irradiation in dry N2. Systematic characterization is performed to understand the surface chemistry and the optical properties of ZnO nanocrystals. Thus obtained ZnO films show unique absorption peak at 294 nm (4.2 eV) (Fig. 1a) and strong tunable photoluminescence in the range of 386-496 nm when expose to UV light, from violet, blue to bluish-green upon increasing time of VUV irradiation (Fig. 1b). Clearly blue-shifted absorption peaks of the VUV treated samples are indicative of quantum-confinement effect, as contrasted to the broad character of the annealed film, which originates from band structure of bulky ZnO. The extension of VUV time only results in increase of absorbance, with no change of the peak wavelength, indicating population increase but no crystal growth by Ostwald ripening during the VUV irradiation. Therefore, the color change of the emitted light should be associated with the change of defect state distribution, rather than the size effect. However, such photoluminescence from defects was fairly strong to be clearly recognized by naked eyes, so that the university logo could be patterned by photomasking VUV to be seen under black light was demonstrated (inset in Fig. 1b).

Figure 1
(Invited) Soft-Matter Robot That Communicates Humans By Contacting
Authors: Kameyama Takaaki , Ogawa Jun , Watanabe Yosuke , Shiblee MD Nahin Islam , Khosla Ajit , Kawakami Masaru , Furukawa Hidemitsu 
Published: December 2020

The research of soft robots composed of soft materials, named "Soft-matter Robotics", has been drawn attention because it is useful as a technology with high interpersonal affinity. The soft-matter robots have a potential advantage in non-destructive behaviors such as picking up an egg without breaking it. On the other hand, IoT / AI technologies such as smart speakers have become popular in the past several years from the viewpoint of software functions of robots. Robots equipped with communication functions based on IoT technology are also gradually permeating our lives.
In the situation where the robot directly touches the human, the soft-matter robot fused with the IoT technology will have the flexibility of the body and the IoT sensor module, so that it is possible to achieve the advanced interaction without damaging the human. However, the softness of the soft-matter robot depends on its material characteristics. It is necessary for realizing the advanced communication to clarify the property of the sensing data of physical contact with human that the installed IoT module can acquire from the material.
This study verifies whether the touching method such as poking, stroking and so on of a three-dimensional object of additive type silicone rubber can be classified through a vibration sensor. Then, we develope a robot that communicates with humans by feeding back the sensed data with light and vibration.

Figure 1
Photoinduced Energy and Electron Transfer in Nanocarbon-Based Donor-Acceptor Systems
Authors: Imahori Hiroshi 
Published: December 2020

Nanocarbons have attracted tremendous attention, as their extended π-conjugation offers intriguing characteristics in optical and electronic properties. These properties suggest their potential utility as basic components in various electronic devices including light-emitting diodes, solar cells, and field-effect transistors.
In this talk, I will give an overview of our recent works focusing on photoinduced electron and energy transfer in nanocarbon-based systems. For instance, excitation of a porphyrin–hexabenzocoronene linked system resulted in selective energy transfer (EnT) from the first singlet excited state (S1) of the hexabenzocoronene to the porphyrin. In contrast, reverse exclusive EnT took place from the first and second singlet excited states (S1 and S2) of the porphyrin to the π-extended hexabenzocoronene in the porphyrin–π-extended hexabenzocoronene linked system. Specifically, ultrafast efficient EnTs from both the S2 and S1 states of the porphyrin to the π-extended hexabenzocoronene are similar to the corresponding ultrafast EnTs from the S2 and S1 states of carotenoids to chlorophylls in natural photosynthesis. Such characteristic photophysical properties will be informative for the elaborated design of nanocarbon-based materials for optoelectronics and solar energy conversion.
[1] T. Umeyama, T. Hanaoka, H. Yamada, Y. Namura, S. Mizuno, T. Ohara, J. Baek, J. Park, Y. Takano, K. Stranius, N. V. Tkachenko, H. Imahori, Chem. Sci., 10, 6642 (2019).
[2] X. Liu, M. Kozlowska,T. Okkali, D. Wagner,T. Higashino, G. Brenner-Weiß, S. Marschner, Z. Fu, Q. Zhang, H. Imahori, S. Bräse, W. Wenzel,C. Wöll, L. Heinke, Angew. Chem. Int. Ed., 58, 9590 (2019).
[3] T. Umeyama, K. Igarashi, D. Sasada, Y. Tamai, K. Ishida, T. Koganezawa, S. Ohtani, K. Tanaka, H. Ohkita, H. Imahori, Chem. Sci., in press.
Contribution of Different Exfoliation Mechanisms in the Bipolar Electrochemical Fabrication of Graphene
Authors: Khakpour Iman , Rabiei Baboukani Amin , Allagui Anis , Wang Chunlei 
Published: December 2020

Since the discovery of graphene, two-dimensional (2D) materials have attracted increasing interest due to their extraordinary properties such as high thermal conductivity, high specific surface area, and broad electrochemical window. In general, different techniques have been employed to fabricate these materials, including chemical vapor deposition, mechanical, chemical, and electrochemical exfoliation. Bipolar electrochemistry (BPE) is one of the newest methods which has been used for the fabrication of 2D materials. In our previous study, a modified BPE concept was developed for simultaneous exfoliating and deposition of both reduced graphene oxide (rGO) and graphene oxide (GO) layers on conductive objects. Although the characteristics of the produced materials have been studied and reported, there are still remaining questions that need more investigations to be answered. The main focus of this study is investigating the active exfoliation mechanisms in the BPE process and finding out the dominant exfoliation reactions (either cathodic or anodic exfoliation).
For this purpose, a novel and unique modified bipolar system has been developed, which could retard either anodic or cathodic exfoliation of graphite by replacing the relevant sites of the bipolar electrode with a platinum wire. This helped to have a better understanding of the source of produced rGO and GO. The morphology and functional groups of deposited materials on both negative and positive feeding electrodes were investigated when the graphite was polarized to either positive or negative potentials. The results proved that both anodic and cathodic exfoliation mechanisms are active at the same time when using graphite as the bipolar electrode. However, the morphology, functional groups, level of oxidation, the bipolar current, and deposition rate vary according to the exfoliation mechanism. The developed modified BPE technique and materials characterizations will be discussed in detail at the conference.
Keywords: Electrochemical exfoliation, bipolar electrochemistry, 2D materials, graphene fabrication
Spacers to Improve Performance and Porosity of Graphene Based Polymer Electrolyte Fuel Cells
Authors: Suter Theo , Clancy Adam , Rubio Carrero Noelia , Heitzmann Marie , Guetaz Laure , Shaffer Milo , Howard Christopher A. , McMillan Paul F. , Brett Dan 
Published: December 2020

Fuel Cell are energy generation alternatives to the traditional fossil fuel dependant transport and energy sectors. A typical polymer electrolyte membrane fuel cell (PEMFC) generates power from the electrochemical reaction between hydrogen and oxygen which forms water. While PEMFC have become increasingly commercialised in the last decade there needs to be a significant cost reduction before the technology sees a much wider uptake. One of the key methods to reduce costs of PEMFCs is to reduce the platinum loading. Significant research has investigated non-platinum groups metals or ultra-low Pt loadings, however these have other technological barriers that need to be surpassed before they are widely commercialised. Increasing the lifetimes of fuel cell stacks is one other method to make costs competitive with traditional power generation. Carbon support corrosion is one of the key decomposition pathways of a fuel cell, this entails degradation and loss of the carbon support with use leading to loss of Pt catalyst, ionomer and reduction of proton and electron conduction.
Highly graphitised carbon supports have been reported to be have superior carbon corrosion resistance compared to commercial carbon black. This has often been attributed to the sp2 carbon framework being more resilient to oxidation. Graphene and few layer graphite (FLG) are composed of sheets of sp2 carbon, high surface areas graphene has been developed. However when deposited as a catalyst layer the sheets restack during drying, forming a dense, low porosity electrode with low current densities. The potential carbon corrosion benefits of graphene cannot be observed reliably when operated at low current densities, it is therefore imperative to develop methods to control the morphology and layering of graphene based electrodes to mitigate this performance loss. In this work we report a series of method that utilises sacrificial additives and spacers to scalably control the morphology of graphene based electrodes. We show significant increases in current density, porosity and Pt utilisation via this method. In addition we discuss the effect of graphene size, source and treatment on performance of PEMFC cathodes.

Figure 1
Silicon Phthalocyanine Modified Multi-Walled Carbon Nanotubes As a Novel Metal-Free Catalyst for the Oxygen Electroreduction
Authors: Kruusenberg Ivar , Kaare Kaitlin , Tsujimoto Masahiko 
Published: December 2020

Finding an alternative catalysts for the oxygen reduction reaction (ORR) has been a key issue in modern electrocatalysis. Traditional platinum-based catalysts are not viable in the long term and thus much effort has been focused on non-precious metal catalysts. Heteroatom doped and metal-heteroatom co-doped carbon materials have emerged as the main candidate for replacing the platinum-based catalysts. Different MN4 macrocycles, such as metal phthalocyanines and porphyrins, have been studied as promising materials to prepare electrocatalysts for ORR in alkaline media [1]. While the development of non-precious metal and non-metal carbon catalysts has gained a lot of attention recently, non-metal phthalocyanines are a less studied topic [2].
In this work a novel catalyst material including multi-walled carbon nanotubes (MWCNT) and silicon phthalocyanine dichloride (SiPcCl2) was synthesised and the electrochemical activity towards the oxygen reduction reaction (ORR) in alkaline media was studied. Different ratios of phthalocyanine-to-nanotubes were pyrolysed at 800 °C. After optimising the ratio of phthalocyanine-to-nanotubes, the pyrolysis process was also carried out at different temperatures, but the results showed that the best temperature for pyrolysis is still 800 °C. ORR activity on SiPc/MWCNT catalyst was studied in 0.1 M KOH by employing rotating disc electrode method. Physical characterisation was carried out with X-ray photoelectron spectroscopy and transmission electron microscopy. The results showed successful incorporation of silicon and nitrogen into the carbon framework. We show that doping MWCNTs with a non-metal phthalocyanine creates a highly active ORR catalyst rivaling the activity of metal-based catalysts in alkaline conditions. This work clearly demonstrates that non-metal macrocyclic compound modified carbons, similar to the the SiPc/MWCNT can be used as alternative cathode catalysts for the metal-air batteries and alkaline membrane fuel cells.
[1] Y. Liu, X. Yue, K. Li, J. Qiao, D.P. Wilkinson, J. Zhang, PEM fuel cell electrocatalysts based on transition metal macrocyclic compounds, Coord Chem Rev. 315 (2016) 153-177.
[2] K.-K. Türk, K. Kaare, I. Kruusenberg, M. Merisalu, U. Joost, L. Matisen, V. Sammelselg, J.H. Zagal, K. Tammeveski, Oxygen electroreduction on zinc and dilithium phthalocyanine modified multiwalled carbon nanotubes in alkaline media, J. Electrochem. Soc. 164 (2017) H338-H344.
Alloy Plating for Improved Molten Salt Reactor Performance
Authors: Hall Timothy , Ahmadi Kamyar , Radhakrishnan Rajeswaran , Snyder Stephen , Raiman Stephen S 
Published: December 2020

The use of molten fluoride salts as a primary coolant within next generation nuclear reactors has the potential to improve efficiency and nuclear reactor safety by operating at low pressures and high temperatures without boiling. However, these coolants will require the development of new corrosion resistant material systems that will have to meet or supersede existing standard codes for these systems. Therefore, state of the art reactors require validation and testing of new material systems that can produce robust component structures and enable them to withstand these corrosive environments. Furthermore, any next generation process to apply protective coatings must allow for a conformal, thick, dense, and bonded materials to be formed onto any low cost ASME material (like 316H SS) that comprises the structure of heat exchanger and containment vessel components.
Within this context, Faraday Technology Inc. is working on developing low cost and high value corrosion-resistant alloy coatings for next generation molten salt reactors with the goal of increasing their functional lifetime, while reducing the component cost. The manufacturing process involves electrodeposition of functionally graded NiMo alloys onto ASME certified substrates and subsequent high temperature corrosion evaluation in molten fluoride salt electrolytes. A wide array of electrolytes and processing parameters were evaluated in order to understand these effects on the deposit composition, structure, and corrosion resistance properties towards the goal of developing an ideal alloy coating. Specifically, we demonstrated the potential to apply graded NiMo coating to the 316H SS surface (Figure 1) and found that a coating composition of ~25% Mo has the potential to improve the components lifetime.

Figure 1