Article
Chemistry, Physical
Yuki Morikuni, K. Kanishka H. De Silva, Pamarti Viswanath, Masanori Hara, Masamichi Yoshimura
Summary: This research article presents a method to fabricate conducting reduced graphene oxide (rGO) monolayer films through methane plasma treatment within few minutes, enabling the nanoscale characterization of local conductivity via conductive atomic force microscopy (C-AFM) and their applicability in highly transparent conducting electrodes.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Ya-Wei Hao, Pan Yang, Li-Jun Yang, Liu-Xin Yang, Li Guo
Summary: This report aims to demonstrate a highly effective method of obtaining graphene oxide (GO)/reduced graphene oxide (RGO) paper through Ultraviolet (UV) laser direct writing. By removing oxygen-containing groups and introducing layered micro-nano structures on one side of the GO film, the prepared GO/RGO papers exhibit anisotropic deformation triggered by ethanol vapor and have potential applications as stimuli-response actuators.
Article
Chemistry, Multidisciplinary
James Nicolas Pagaduan, Ayush Bhardwaj, Tailynn Y. McCarty, Stephan Kraemer, Cathal J. Kearney, James J. Watkins, Todd Emrick, Reika Katsumata
Summary: This study reports a simple and scalable method for fabricating porous carbon materials using low-cost chemical compounds while maintaining morphological and chemical control. Nitrogen and oxygen-doped porous carbon frameworks were synthesized by rapid thermal annealing and subsequent burning of degradable components. Introduction of boron-containing reagent resulted in boron doping and pore size reduction, enhancing material performance.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Afsaneh L. Sanati, Alexandre Chambel, Pedro Alhais Lopes, Timur Nikitin, Rui Fausto, Mahmoud Tavakoli
Summary: This study demonstrates a method for large-scale, efficient, and low-cost fabrication of highly transparent conductors. The method involves spray coating a low-cost graphene oxide (GO) solution and then using a nanosecond fiber laser for reduction and thinning. By adjusting the laser parameters, different levels of transparency, conductivity, and full ablation can be achieved.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Chemistry, Physical
Jiwon Kim, Junhyeok Kang, Jeong Pil Kim, Ju Yeon Kim, Ji Hoon Kim, Ohchan Kwon, Dae Woo Kim
Summary: A large-area nanoporous multilayer graphene oxide (NMG) membrane was prepared using slot-die coating and confined thermal treatment. The optimized NMG membrane exhibited high ethanol permeance and sharp molecular weight cut-off, and it showed enhanced adhesion between graphene and the polymeric support, resulting in a mechanically stable membrane operation under cross-flow conditions for 30 days.
Review
Chemistry, Physical
Aamir Razaq, Faiza Bibi, Xiaoxiao Zheng, Raffaello Papadakis, Syed Hassan Mujtaba Jafri, Hu Li
Summary: This paper provides a comprehensive review of the recent progress in the synthesis and applications of graphene-based composites in the field of flexible devices. It also highlights the difficulties and challenges in the development of graphene, serving as a valuable reference for further innovation.
Article
Chemistry, Physical
Sooyeon Jeong, Sunhye Yang, Byeong Guk Kim, Hye Jung Lee, Jung Jun Bae, Jung Hun Kim, Jung Mo Kim, Wonki Lee, Jun Yeon Hwang, Soyeon Choi, Hee Jin Jeong, Jong Hwan Park, Young Chul Choi, Geon-Woong Lee, Seung Yol Jeong
Summary: In this study, a potential approach for the production of high-quality quasi-defect-free reduced graphene oxide (QrGO) with semimetallic transport behavior was presented. The QrGO exhibited metallike behavior, environmental stability, and high electrical conductivity, showing great potential for large-scale production and practical applications.
Article
Chemistry, Physical
Frantisek Zelenak, Maria Kovacova, Zdenek Moravec, Mirko Cernak, Richard Krumpolec
Summary: This study presents a scalable, fast, safe, and eco-friendly method for preparing highly conductive rGO thin paper. The method involves the use of a plasma source and spraying cycles to prepare thin GO paper, followed by rapid GO reduction-exfoliation to create highly porous rGO paper within seconds. The short duration and scalability of this method make it suitable for large-scale industrial applications.
Article
Chemistry, Physical
Sharad Kumar Yadav, D. Manikandan, Chob Singh, Mukesh Kumar, G. Aswathy, Sundara Ramaprabhu, Vishal V. R. Nandigana, Pramoda K. K. Nayak
Summary: Blue energy, derived from the osmotic energy of a salinity gradient, shows promise as a non-intermittent renewable energy source. However, the limitations of membrane-based technology, particularly poor membrane performance, hinder its large-scale viability. A solution to this bottleneck is the use of atomically thin 2D nanoporous materials with high surface charge density, leading to improved energy generation. While nanoporous membranes exhibit high performance, technical challenges and ion concentration polarization make them non-viable. Conversely, mesoporous and microporous structures in 2D membranes offer improved energy generation with low fabrication complexity.
Article
Nanoscience & Nanotechnology
Xiyu Hu, Xiaoshuang Wei, Aditi R. Naik, Laura C. Bradley, James J. Watkins
Summary: This study successfully fabricated reliable and scalable micro-valves on flexible materials, which are attractive for fluid management and enhanced device functionality for disposable microfluidic applications. A microfluidic electrowetting valve was created on a poly(ethylene terephthalate) substrate using the principle of electrowetting-on-dielectric. Copper electrodes were fabricated using inkjet-printing and intense pulsed light sintering, and a hydrophilic and a hydrophobic electrode were required for valve actuation. Systematic experiments were performed to study the effect of dielectric layer thicknesses and applied voltages on the droplet contact angle. The polymer-coated copper electrodes remained stable and showed consistent wetting behavior at low voltages. Additionally, a microfluidic device was fabricated to demonstrate independent actuation of two electrowetting valves. These results present significant opportunities for integrating copper electrowetting valves into low-cost microfluidic devices using scalable techniques.
MICROFLUIDICS AND NANOFLUIDICS
(2023)
Article
Chemistry, Physical
Yiwen Chen, Xinyun Su, Dominic Esmail, Emily Buck, Simon D. Tran, Thomas Szkopek, Marta Cerruti
Summary: A dual-templating method is developed to fabricate graphene oxide (GO) scaffolds with interconnected hierarchical porosity for bone tissue engineering. The method involves freezing and drying high internal phase emulsions stabilized by GO sheets, resulting in the templating of large and small pores by oil droplets and ice crystals, respectively. This approach enables the synthesis of complex hierarchical architectures in reduced graphene oxide (rGO) and GO composite scaffolds.
Article
Chemistry, Physical
Qianyu Ji, Bowen Wang, Yajuan Zheng, Fanguang Zeng, Bingheng Lu
Summary: Holey graphene nanosheets are produced through a unique production method, with low defects and high electrical conductivity, exhibiting various pore structure characteristics.
APPLIED SURFACE SCIENCE
(2021)
Article
Nanoscience & Nanotechnology
Sascha Morlock, Senthil K. Subramanian, Athina Zouni, Fred Lisdat
Summary: The study focuses on using reduced graphene oxide as an electrode material to construct a three-dimensional structure for semi-artificial photosynthesis. By optimizing electrode preparation and protein immobilization, the performance and thickness of the electrode can be adjusted to achieve higher photocurrents. The operational stability and performance at low illumination intensities have been analyzed and show promising results.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Materials Science, Multidisciplinary
Congming Li, Xiangming Li, Wei Yu, Ronglin Xiao, Fei Huang, Hongmiao Tian, Chunhui Wang, Xiaoliang Chen, Jinyou Shao
Summary: This study presents a method for mass production of dense and highly ion conductive graphene. The method involves turbulent flow and capillary compression at violent boiling temperature to fabricate turbostratic graphene, achieving a balance between high density and high ion conductivity, as well as large-scale production. The turbostratic graphene exhibits enhanced ion conductivity, high density, and volumetric capacitance, marking a milestone in capacitive energy storage.
Article
Energy & Fuels
Sevda Yetiman, Hilal Pecenek, Fatma Kilic Dokan, M. Serdar Onses, Erkan Yilmaz, Ertugrul Sahmetlioglu
Summary: This study presents the microwave-assisted preparation of cobalt oxide-based nanocomposite electrodes doped with carbon dots and reduced graphene oxide. The electrodes with carbon dots exhibit the highest specific capacitance and good rate capability, even at high current densities. The optimized electrodes are used to fabricate a symmetric supercapacitor with high specific capacitance and long cycle life.
JOURNAL OF ENERGY STORAGE
(2022)
Article
Nanoscience & Nanotechnology
Soumya Biswas, Saurabh Singh, Shubham Singh, Shashwata Chattopadhyay, K. Kanishka H. de Silva, Masamichi Yoshimura, Joy Mitra, Vinayak B. Kamble
Summary: By selectively enhancing phonon scattering through Al doping and reduced graphene oxide (RGO) encapsulation, a significant increase in the zT value of ZnO has been demonstrated, making it a promising candidate for high-temperature thermoelectric power generation applications. Innovations in electrical and thermal conductivities lead to improved power factors and overall TE efficiency.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
K. Kanishka H. De Silva, Pamarti Viswanath, V. Kesava Rao, Seiya Suzuki, Masamichi Yoshimura
Summary: A new insight into the characterization of GO and thermally reduced GO monolayer flakes deposited on different commonly used Si-based substrates by Raman spectroscopy along with optical visualization has been reported. The study found that dielectric substrates with lower reflectance in the visible range provide better optical contrast and generate intense Raman signals under normal white light illumination. Additionally, a Si substrate with a 90 nm SiO2 layer was shown to offer the highest I-G'/I-G ratio and better optical visibility for monolayer RGO flakes.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Physics, Applied
Vasilios Karanikolas, Seiya Suzuki, Shisheng Li, Takuya Iwasaki
Summary: This Perspective presents the application of polariton modes in two-dimensional materials to enhance and control light-matter interactions at the nanoscale. By analyzing the optical response of various 2D material nanostructures, the hybrid light-matter modes are evaluated.
APPLIED PHYSICS LETTERS
(2022)
Article
Multidisciplinary Sciences
Gamaralalage R. A. Kumara, Herath Mudiyanselage G. T. A. Pitawala, Buddika Karunarathne, Mantilaka Mudiyanselage M. G. P. G. Mantilaka, Rajapakse Mudiyanselage G. Rajapakse, Hsin-Hui Huang, K. Kanishka H. De Silva, Masamichi Yoshimura
Summary: A novel and simple flotation technique has been developed to prepare high-purity graphite from impure graphite, which is environmentally friendly and cost-effective. The floated graphite has higher purity, smaller crystallite sizes, and potentially increased carbon content, enhancing the value of graphite.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Multidisciplinary
K. Kanishka H. De Silva, Kazuma Shibata, Pamarti Viswanath, Hsin-Hui Huang, Masamichi Yoshimura
Summary: This article introduces a facile two-step reduction method to fabricate reduced graphene oxide (RGO) films with remarkable structural qualities. The method involves chemical reduction followed by thermal reduction to repair lattice vacancies, resulting in RGO films with high structural quality and electrical properties approaching pristine graphene.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Physics, Applied
Norihiro Fukaya, K. Kanishka H. De Silva, Masamichi Yoshimura, Hiroya Tanaka
Summary: In this study, the morphologies of graphene oxide and polyethyleneimine composite membranes were investigated. The research revealed that polyethyleneimine can reduce the oxygen functional groups in the membranes. It was also found that the loss of hydroxyl and carboxyl groups in the membranes resulted in increased hydrophobicity and changed permeability.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Prerna Joshi, Rohit Yadav, K. Kanishka H. De Silva, Masanori Hara, Hayato Shibuya, Yukihiro Motoyama, Masamichi Yoshimura
Summary: The study investigates the synthesis of nitrogen-doped graphene oxide from precursor graphite of different sizes and its impact on the OER activity of IrO2 in an acidic medium. The nitrogen-doped supports are expected to exhibit various structural functionalities, and selecting the appropriate flake size is crucial for enhancing the stability of catalysts.
Review
Materials Science, Multidisciplinary
K. Kanishka H. De Silva, Hsin-Hui Huang, Pamarti Viswanath, Rakesh Joshi, Masamichi Yoshimura
Summary: This review article highlights the characterization of electrical properties of graphene-based materials using atomic force microscopy techniques, providing important insights into the correlation between structure and electrical properties at the nanoscale.
JOURNAL OF MATERIALS RESEARCH
(2022)
Article
Microscopy
Kaname Yoshida, Hsin-Hui Huang, Tomohiro Miyata, Yohei K. Sato, Hiroshi Jinnai
Summary: The mechanisms of electron irradiation damage to epoxy resin samples were evaluated using electron diffraction patterns and electron energy-loss spectra. The electron diffraction patterns showed three indistinct halo rings, with one ring corresponding to an intermolecular distance of approximately 6.4 angstrom rapidly degrading, possibly due to cross-linking between molecular chains. The degree of electron irradiation damage changed with the accelerating voltage, and the tolerance dose limit of the epoxy resin improved at higher accelerating voltages. Changes in low-loss electron energy-loss spectra indicated significant mass loss of the epoxy resin in the early stage of electron irradiation.
Article
Physics, Multidisciplinary
Seiya Suzuki, Yoshihiro Nemoto, Natsumi Shiiki, Yoshiko Nakayama, Masaki Takeguchi
Summary: Germanene, a two-dimensional germanium material similar to graphene, has unique topological properties that make it a promising candidate for next-generation electronics. However, the lack of chemical stability in germanene has hindered the development of germanene electronic devices. In this study, the behavior of germanium at high temperatures was observed using transmission electron microscopy (TEM) on a graphene/germanium/graphene encapsulated structure. The results demonstrated that Germanium can exist as a liquid phase between graphene layers at temperatures above its melting point, and that it can incorporate surrounding amorphous germanium to grow larger crystals. These findings provide important insights for the growth of germanene at solid interfaces.
ANNALEN DER PHYSIK
(2023)
Article
Chemistry, Multidisciplinary
Kohei Era, Katsutoshi Sato, Shin-ichiro Miyahara, Takahiro Naito, Kanishka De Silva, Saeid Akrami, Hiroshi Yamada, Takaaki Toriyama, Tomokazu Yamamoto, Yasukazu Murakami, Ken-ichi Aika, Koji Inazu, Katsutoshi Nagaoka
Summary: This study reports the development of a Fe/K(3)/MgO catalyst via an impregnation method, which exhibits high activity for ammonia synthesis under mild reaction conditions. K doping improves the catalyst's performance, and increasing the pressure further enhances the ammonia synthesis rate.
Article
Chemistry, Physical
Hsin-Hui Huang, Shunsuke Kobayashi, Toyokazu Tanabe, Kaihei Komiyama, Miwa Saito, Teruki Motohashi, Akihide Kuwabara
Summary: This study reveals the crystal and electronic structures of YBaCo4O7+delta material synthesized at a low temperature, and discovers the significant influence of structural defects and surface states on oxygen storage.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Chemistry, Multidisciplinary
Seiya Suzuki, Takuya Iwasaki, K. Kanishka H. De Silva, Shigeru Suehara, Kenji Watanabe, Takashi Taniguchi, Satoshi Moriyama, Masamichi Yoshimura, Takashi Aizawa, Tomonobu Nakayama
Summary: Germanene, a 2D honeycomb germanium crystal, is grown at graphene/Ag(111) and hexagonal boron nitride (h-BN)/Ag(111) interfaces by segregating germanium atoms. A simple annealing process in N-2 or H-2/Ar at ambient pressure leads to the formation of germanene, indicating that an ultrahigh-vacuum condition is not necessary. The grown germanene is stable in air and uniform over the entire area covered with a van der Waals (vdW) material.
ADVANCED FUNCTIONAL MATERIALS
(2021)
