Article
Chemistry, Physical
A. Falamas, I. Marica, F. Nekvapil, M. Stefan, G. S. Macavei, L. Barbu-Tudoran, C. Farcau
Summary: In this paper, we developed ZnO nanostructures based platforms for surface enhanced fluorescence emission. ZnO nanoparticles were prepared using a simple chemical precipitation method and decorated with Au nanoparticles. Rhodamine 6G-containing films were designed by incorporating nanostructures in a PVA matrix, which hindered the aggregation of the nanostructures and improved film formation capability. Surface enhanced fluorescence emission of Rhodamine 6G was achieved in the presence of ZnO nanoparticles embedded in the PVA matrix, dependent on the concentration of the fluorophore and ZnO nanoparticles. Au decorated ZnO nanocomposites exhibited no fluorescence enhancement and both types of nanostructures quenched the dye outside of the PVA environment. Time-resolved fluorescence investigations showed that neither ZnO NPs nor Au decorated ZnO nanocomposites modified the dye's lifetime in the presence of PVA, while an additional decay pathway emerged in the absence of the PVA matrix, leading to modified fluorescence lifetime.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Nizar Ben Moussa, Mohamed Lajnef, Nessrine Jebari, Cedric Villebasse, Fabien Bayle, Julien Chaste, Ali Madouri, Radouane Chtourou, Etienne Herth
Summary: In this study, low-cost sol-gel spin-coating technique was used to synthesize eco-friendly ZnO multilayer films with excellent optical properties and specific orientation suitable for piezoelectric applications. The ZnO sol-gel thin-films using precursor solutions of molarity 0.75 M exhibited an average optical transparency above 98% and an optical band gap energy of 3.42 eV, showing potential for eco-friendly and cost-effective applications in complementary metal-oxide-semiconductor (CMOS) and integrated circuits (IC).
Article
Chemistry, Multidisciplinary
Meiling Zhang, Jean-Marie Poumirol, Nicolas Chery, Herve Rinnert, Alaa E. Giba, Remi Demoulin, Etienne Talbot, Fuccio Cristiano, Teresa Hungria, Vincent Paillard, Fabrice Gourbilleau, Caroline Bonafos
Summary: We successfully demonstrate the experimental realization of plasmonic hyperdoped Si nanocrystals embedded in silica by a combination of sequential low energy ion implantation and rapid thermal annealing. We find that phosphorus dopants are incorporated into the nanocrystal cores at concentrations up to six times higher than P solid solubility in bulk Si. We explain the nanocrystal growth at high P doses as a result of Si recoiling atoms generated in the matrix by P implantation, which enhance Si diffusivity and provide the Si nanocrystals.
Article
Chemistry, Physical
Ivan Shtepliuk, Rositsa Yakimova
Summary: The combination of wide-band gap semiconductors, such as zinc oxide (ZnO), and graphene quantum dots (GQDs) is a promising strategy to manipulate the properties of GQDs and create new functionalities. This study presents a theoretical design of ZnO-embedded graphene quantum dots, which have not yet been synthesized. The structure and light absorption properties of these hybrid materials are analyzed, with a focus on the photoexcited states. The results provide insights into the nature of light absorption in ZnO-embedded graphene quantum dots and lay the foundation for future experimental studies on these materials.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Applied
Benjamin Malfait, Laurent Paccou, Natalia T. Correia, Yannick Guinet, Alain Hedoux
Summary: A very unusual amorphous-amorphous two-step transformation of indomethacin confined within MCM-41 mesoporous silica was observed, involving the growth of gamma-nanocrystals followed by their transformation to an undercooled liquid state structurally different from the original liquid. The unstable nanocrystals were explained to be a result of high specific area imposed by geometrical confinement, with dissolution mechanism similar to digestive ripening.
MICROPOROUS AND MESOPOROUS MATERIALS
(2021)
Article
Chemistry, Analytical
Qianqian Liu, Xiaoxuan Chen, Hongliang Li, Yanqing Guo, Jie Song, Wenxing Zhang, Chao Song, Rui Huang, Zewen Lin
Summary: Luminescent amorphous silicon nitride-containing dense Si nanodots were prepared using very-high-frequency plasma-enhanced chemical vapor deposition at 250 degrees C, and the influence of thermal annealing on photoluminescence was studied. Thermal annealing at 1000 degrees C significantly enhanced the photoluminescence intensity, showing nanosecond recombination dynamics, and the peak position was independent of the excitation wavelength and temperatures. The enhanced photoluminescence was suggested to be from the increased density of radiative centers related to Si dangling bonds and nitrogen bonding configuration reconstruction.
Article
Engineering, Electrical & Electronic
P. K. Upadhyay, Neerav Sharma, Shashank Sharma, Ravi Sharma
Summary: This paper presents the PL and TL studies of undoped and Eu-doped ZnO nanophosphors, characterized by XRD and SEM. Eu-doped samples showed an additional XRD peak attributed to Europium oxide, with sizes ranging from 55 to 80 nm. The TL intensity increased linearly with gamma dose, suggesting potential for dosimetry applications.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Article
Optics
Shukun Li, Huanqing Chen, Menglai Lei, Guo Yu, Peijun Wen, Jianbo Fu, Shengxiang Jiang, Hua Zong, Dong Li, Xiaodong Hu
Summary: In this study, high-quality SiN:H films embedded with Si quantum dots (QDs) were fabricated and prepared by reactive facing target sputtering. The size of Si QDs in the films can be tuned from 3.87 nm to 1.40 nm, showing color-tunable photoluminescence from red to blue in the visible region. The microstructure evolution and optical properties of the films were analyzed by various measurements, and their potential applications in high-performance EL SiN-based LEDs were explored.
JOURNAL OF LUMINESCENCE
(2023)
Article
Chemistry, Multidisciplinary
Shankari Nadupalli, Sergej Repp, Stefan Weber, Emre Erdem
Summary: This study investigates the intrinsic defect structure of ZnO and its influences. The results demonstrate that the concentration and position of intrinsic defects in ZnO can be tuned by changing the nanocrystal size, while emissions can be tuned by post-annealing treatments.
Article
Chemistry, Multidisciplinary
Islam Mohammad Shafiqul, Raj Deep, Jie Lin, Toshiyuki Yoshida, Yasuhisa Fujita
Summary: In this study, nitrogen-doped zinc oxide nanoparticles were successfully synthesized using the gas evaporation method with DC arc plasma. The nitrogen concentration was found to have an impact on the Raman spectra and photoluminescence spectra of the nanoparticles.
Article
Chemistry, Physical
Xiaonan Xi, Yuanyuan Li, Tianyuan Liang, Huaxin Wu, Ruonan Miao, Chao Gu, Jiyang Fan
Summary: The study presents the fabrication of epitaxial pyramidal ZnO-Au HNCs and investigates their unique photophysical properties. Strong coupling between ZnO NC green defect-related recombination and localized surface plasmon resonance of Au nanospheres leads to nearly complete quenching of green defect luminescence in the ZnO NCs.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Linlin Liu, Daitao Kuang, Lizhen Hou, Heng Luo, Lianwen Deng, Shiliang Wang
Summary: C-based microwave absorbers, such as hard carbon-based composites, have been studied for over 80 years and show promise as advanced high-performance microwave absorbers. However, little research has been done on the microwave absorption properties of hard carbon-based composites. In this study, composites composed of layered hard carbon embedded with ZnO nanoparticles were synthesized and found to exhibit excellent microwave absorption properties, which could offer a new insight for the design of high-performance microwave absorbers.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Nanoscience & Nanotechnology
Lisa Sarkar, Mudigunda Sushma, Bhavani Prasad Yalagala, Aravind Kumar Rengan, Shiv Govind Singh, Siva Rama Krishna Vanjari
Summary: This paper presents a flexible nanogenerator using a Silk-Zinc Oxide (ZnO) composite. The composite is prepared by synthesizing Zinc Oxide nanoparticles and coating them onto silk to form a film. The composite exhibits good biocompatibility and adjustable piezoelectric properties, making it suitable for the fabrication of efficient nanogenerators.
Article
Chemistry, Multidisciplinary
Wenke Li, Kai Li, Xiujian Zhao, Chao Liu, Francois-Xavier Coudert
Summary: In this study, the nature of excited states of CdSe QDs embedded in inorganic matrices was investigated using TDDFT. The undercoordinated Se atoms and nonbridging oxygen atoms at the QD/glass interface were found to be responsible for the low photoluminescence quantum yield. The predicted photoluminescence performance for CdSe QDs in different matrices was validated by experiments. This study has significant implications for the fabrication of highly luminescent glasses.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Materials Science, Multidisciplinary
Abdel Khaleq Mousa Alsmadi, Belal Salameh, Maryam Barhoush
Summary: In this study, high-quality copper-doped ZnO films were prepared using the standard spray pyrolysis method. The correlation between magnetic ordering and native defect states in the ZnO lattice was systematically investigated. The results showed that the detected ferromagnetic ordering is intrinsic and induced by the copper dopants. An improvement in ferromagnetic ordering was observed with increasing copper dopant concentration, which was correlated with an increase in oxygen vacancy and zinc interstitial concentrations and a slight decrease in the concentration of zinc vacancies and oxygen interstitial levels. The magnetic ordering mechanism was associated with the long-range ferromagnetic coupling between copper ions mediated by intrinsic defects.
Article
Environmental Sciences
Toshio Itoh, Yoshitake Masuda, Ichiro Matsubara, Junichirou Arai, Woosuck Shin
Summary: This study analyzed the temporal variation of VOCs composition in four essential oils. The results revealed that the concentration level of VOCs in the oils varied with diffusion time and equilibrium concentration with the liquid phase. It was confirmed that the total concentration of VOCs diffused by the ultrasonic diffuser in room air was very low.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH
(2022)
Article
Chemistry, Analytical
Yoshitake Masuda
Summary: This review focuses on tin oxide nanomaterials, which are actively researched as semiconductor-type gas sensors. The development and applications of novel tin oxide nanomaterials in the past decade are discussed, with a focus on how dimensions and morphology affect sensing performance. The dendritic structure formed by 2D nanosheets connected by crystal growth points towards future sensor development, while the high gas adsorption performance and reactivity of metastable crystal planes provide guidance for future sensor development.
SENSORS AND ACTUATORS B-CHEMICAL
(2022)
Article
Chemistry, Multidisciplinary
Chunyan Li, Pil Gyu Choi, Yoshitake Masuda
Summary: NiO nanosheets were synthesized using a facile solvothermal method and used as gas sensors to analyze the exhaled biomarker of psychological stress, allyl mercaptan (AM) gas. MnO2 nanosheets were also synthesized onto the surfaces of the NiO nanosheets to enhance gas-sensing performance. The gas-sensing response of the NiO nanosheet sensor was found to be higher compared to the MnO2@NiO nanosheet sensor.
Article
Materials Science, Ceramics
Kyusung Kim, Pil Gyu Choi, Toshio Itoh, Yoshitake Masuda
Summary: Atomic defects can enhance the catalytic efficiency of metal oxides, making chemical reactions easier. In this study, porous ZnO nanobelts with atomic step structures were fabricated for ultrasensitive gas sensing of acetone, ethanol, and isoprene at the parts-per-billion level.
INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY
(2023)
Article
Materials Science, Ceramics
Yoshitake Masuda
Summary: Cold crystallization and morphology control have been achieved for ZnO nanostructures, which can be used in various devices such as sensors, batteries, and catalysts.
INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Pil Gyu Choi, Yoshitake Masuda
Summary: Mental stress management is crucial for human health as excessive and sustained mental stress can cause harm. This study focuses on allyl mercaptan, a biomarker associated with mental stress, and utilizes a nanosheet-type tin oxide gas sensor array to detect it. Gas classification models are built using supervised learning algorithms and principal component analysis, providing accurate forecasts for allyl mercaptan.
SCIENTIFIC REPORTS
(2022)
Article
Materials Science, Ceramics
Kim Kyusung, Chunyan Li, Pil Gyu Choi, Toshio Itoh, Yoshitake Masuda
Summary: A simple synthesis method of freestanding Zinc hydroxidefluoride (ZnOHF) nanobelt as 1D material without seed or substrate using aqueous solutions was introduced in this study. The growth direction of the nanobelt can be controlled by the concentration of HMT, with lower HMT concentration resulting in broader nanobelt width.
JOURNAL OF ASIAN CERAMIC SOCIETIES
(2022)
Article
Nanoscience & Nanotechnology
Takuma Ema, Pil Gyu Choi, Seiichi Takami, Yoshitake Masuda
Summary: CeO2 nanocubes and nanooctahedrons with different facets were fabricated by controlling the morphology of CeO2 nanoparticles. The gas sensors based on these CeO2 nanoparticles exhibited enhanced sensing performance to various chemical species and show potential for disease diagnosis.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
B. Veena, S. Pavithra, M. Seetha, A. Sakunthala, Yoshitake Masuda
Summary: In order to meet the increasing demand for portable charge storage devices, CeO2 nanoparticles were synthesized as a supercapacitor material through a cost-effective method, and chromium was doped to improve its efficiency and stability.
Article
Materials Science, Ceramics
Kyusung Kim, Pil Gyu Choi, Toshio Itoh, Yoshitake Masuda
Summary: By changing the supply rate of hydroxide ions, we can control the morphology of ZnO nanomaterial and improve the sensitivity of metal-oxide-semiconductor gas sensors.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Krishnaprasanth Alageshwaramoorthy, Pandian Mannu, Seetha Mahalingam, Ta Thi Thuy Nga, Han-Wei Chang, Yoshitake Masuda, Chung-Li Dong
Summary: In this study, the novel CuTa2O6 phase was synthesized by hydrothermal and calcination processes. X-ray diffraction confirmed the presence of different phases, with a phase transition to cubic crystal structure at high temperatures. Optical studies and FESEM images provided further characterization of the material. The photocatalytic activity of CuTa2O6 was evaluated for the degradation of MO dye and showed promising results.
FRONTIERS IN CHEMISTRY
(2023)
Article
Chemistry, Physical
Pil Gyu Choi, Yoshitake Masuda
Summary: A thin film of nanosheet-type tin oxide (SnO2) was synthesized on a sensor chip using an aqueous solution process. Au-Pd was then loaded onto the film's surface through ion sputtering. The sensor signal response of the Au-Pd loaded tin oxide to hydrogen was higher than that of the bare tin oxide, while its response to methane gas decreased. The designed nanosheet has potential applications as a hydrogen sensor array.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Engineering, Environmental
Chunyan Li, Pil Gyu Choi, Yoshitake Masuda
Summary: Gas sensors with high sensitivity and selectivity are crucial for practical applications, such as distinguishing target molecules in volatile organic compound detection, real-time security alerts, and clinical diagnostics. In this study, a large-lateral-area SnO2 nanosheet sensor was successfully synthesized via a one-step aqueous solution process. The SnO2 sensor exhibited remarkable sensitivity and anti-interference ability towards acetone, with excellent reproducibility and long-term stability. The ultrasensitive response of the SnO2 nanosheets can be attributed to their specific loose structure, small grain size, and metastable crystal facets.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Chemistry, Analytical
Toshio Itoh, Yutaro Koyama, Yuichi Sakumura, Takafumi Akamatsu, Akihiro Tsuruta, Yoshitake Masuda, Woosuck Shin
Summary: We investigated the discriminant method for identifying volatile organic compounds (VOCs) in exhaled breath under both contaminated and purified air conditions using multiple semiconductive gas sensors and linear discriminant analysis (LDA) technique. Our developed discriminant method was used to analyze the resistance changes in sensor signals in the LDA space. The target gases were discriminated based on the angle of the locus of the test data in the 2-D LDA space. Our results demonstrated the feasibility of this method in discriminating target gases under contaminated air conditions.
SENSORS AND ACTUATORS B-CHEMICAL
(2023)
Article
Chemistry, Physical
Kyusung Kim, Pil Gyu Choi, Toshio Itoh, Yoshitake Masuda
Summary: By decorating ZnO nanobelts with atomic step structures, the gas sensing performance can be improved to detect acetone at the ppt level. The atomic step edges promote electron transfer and restrict gas diffusion on the flat surface to achieve sensitivity.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
