Article
Spectroscopy
Reshma P. Radhakrishnan, Arun K. Prasad
Summary: In this study, a multi-modal approach was used to investigate the sensing mechanism of NH3 gas by V2O5 nanoparticles in ambient air. The results showed that V2O5 nanoparticles with an average size of 49 nm exhibited a superior sensor response towards 1 ppm of NH3 gas. The presence of NH3 induced electron doping, resulting in conduction band filling and an increase in the optical band gap. The vanadyl oxygen site was found to be the most active in the sensing process.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2023)
Article
Materials Science, Multidisciplinary
Sameh M. Elghnam, Youssef H. Abdelalim, Mahmoud A. Hamad
Summary: The effect of weathering exposure on the optical absorption characteristics of LDPE grad-LA071 has been investigated. It has been found that the optical absorption of LDPE grad-LA071 decreases exponentially with wavelength in different durations of time. In addition, the optical absorption increases significantly with exposure time, especially at high frequencies, suggesting that LDPE grad-LA071 is a practical candidate for a selective filter for UV light. Therefore, it can be used as a UV light mask in semiconductor devices and as a protective shield for solar cells. Furthermore, the LDPE grad-LA071 film can be used in packaging to extend the lifespan of various items.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Chemistry, Applied
Xu Zhang, Limiao Shi, Mark A. Fox, Adam Barlow, Mahbod Morshedi, Marie P. Cifuentes, Mark G. Humphrey, Olivier Mongin, Frederic Paul, Christine O. Paul-Roth
Summary: The synthesis of a series of four porphyrin derivatives based on a meso-tetrafluorenylporphyrin core functionalized with organoruthenium endgroups is reported. The multipolar assemblies show potential electron-donors at the periphery and potential electron-acceptors at the central core. The extended networks incorporating polarizable organometallic units behave as nonlinear absorbers in the near-IR range, and the role of peripheral transition metal centers on the third-order NLO properties is discussed.
Article
Biochemistry & Molecular Biology
Xiaoke Yin, Xiaojun Li
Summary: The molecular structures, electronic properties, and UV-vis absorption spectra of MGP oxides were theoretically calculated using DFT. The chemical stability of the oxides decreases gradually, with the adsorption of oxygen atoms altering their electronic structures.
JOURNAL OF MOLECULAR MODELING
(2021)
Review
Chemistry, Analytical
Nejla Cini, Aysegul Golcu
Summary: This review highlights the most recent spectrophotometric approaches applied to analyze various classes of drugs in biological media and/or dosage forms, with a focus on direct and derivative UV/UV-Vis spectrophotometry. The versatility, ease of application, low cost, and fast response of spectrophotometric methods make them one of the most preferable methods in drug analysis, providing high accuracy and precision with a wide linear range.
CURRENT ANALYTICAL CHEMISTRY
(2021)
Article
Biochemical Research Methods
Xiaowei Chen, Gaofang Yin, Nanjing Zhao, Ruifang Yang, Meng Xia, Chun Feng, Yunan Chen, Ming Dong, Wei Zhu
Summary: This paper proposed a turbidity compensation method based on Mie scattering theory to improve the accuracy of COD measurement by UV-Vis spectroscopy. By analyzing the complex refractive index of particles in water and establishing a turbidity compensation model, the COD concentration inversion was achieved using the PLS algorithm. The method is simple, fast, and highly accurate, and can be useful for online COD measurement.
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2021)
Article
Metallurgy & Metallurgical Engineering
Weibing Guo, Wenshan Bian, Haitao Xue, Xiaoming Zhang
Summary: In this study, the effects of Al, Zn, and Zr additions on the interfacial bonding properties of Mg/SiC were investigated comprehensively using first-principle calculations. The results showed that Zn dopants were ineffective in improving the bonding strength, Al atoms only strengthened the C-T interface, while Zr addition significantly enhanced the interfacial bonding strength.
JOURNAL OF MAGNESIUM AND ALLOYS
(2022)
Article
Physics, Multidisciplinary
Shamim Aslam, Ms Amiza, Abubaker Siddig, Nasser Saleh Al Zayed, Shahid M. Ramay, Murtaza Saleem
Summary: This study demonstrates that the incorporation of Zn in ceria can significantly improve its electronic and optical properties, making it more suitable for modern electronic devices.
Article
Geochemistry & Geophysics
Charles A. Geiger, Michail N. Taran
Summary: This study measured the UV/Vis/NIR absorption spectra of different composition garnets and identified a broad absorption band assigned to an IVCT mechanism. This mechanism, commonly observed in iron minerals, was not previously observed in garnets. The IVCT mechanism in garnets is influenced by composition and growth conditions.
AMERICAN MINERALOGIST
(2023)
Article
Chemistry, Inorganic & Nuclear
Marek Eggen, Andrzej Kedziorski, Rafal Janicki, Maria Korabik, Marek Krosnicki
Summary: This paper discusses the ab initio calculations of the electronic structure and magnetic properties of the Ho-EDTA complex, and examines the influence of different parts of the environment on its properties.
Article
Chemistry, Physical
Rui-Zhou Zhang, Xing-Hao Cui, Hong-Ling Cui, Xiao-Hong Li
Summary: The electronic and magnetic properties of Sc2CF2 and its doped compounds were investigated using first-principles calculations. The results show that certain doping elements can enhance the stability of the material and induce semiconductor-metal transition or semimetallic properties. In addition, some dopants also lead to significant magnetism. Charge transfer and other properties such as effective mass and electron localization were also analyzed.
APPLIED SURFACE SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Ming-Zhu Liu, Xiao-Hong Li, Xing-Hao Cui, Rui-Zhou Zhang, Hong-Ling Cui
Summary: The electronic and optical properties, work function and quantum capacitance of Janus Hf2COT (T =-Br,-Cl, -F, -OH,-P, -S,-Se) MXene are investigated using density functional theory. The analysis of binding energies and formation energies indicate their structural stability. The asymmetric functional group changes Hf2CO2 from a semiconductor to metal Hf2COT. Hf2COF and Hf2COOH have potential applications for optoelectronic devices.
Article
Biophysics
Wei Yang, Jianwen Fei, Wei Xu, Hongyan Jiang, Marwan Sakran, Junli Hong, Wanying Zhu, Xuemin Zhou
Summary: A biosensor based on Fe3O4@MnO2 NS was constructed for colorimetric determination of uric acid in plasma. The method allows quantitative detection of UA through specific catalytic reactions, and colorimetric analysis can be performed through naked eye, smartphone, and UV-vis spectrophotometer.
COLLOIDS AND SURFACES B-BIOINTERFACES
(2022)
Article
Chemistry, Physical
Jianqiang Zhao, Yue Zhang, Lihua Gan, Guanlei Wang
Summary: This study combined experimental measurements and DFT calculations to investigate UV-vis absorption spectra. The results showed that the rotation mechanism is favored in the first excited state for DHA and DEA, with a good agreement with experimental data.
COMPUTATIONAL AND THEORETICAL CHEMISTRY
(2021)
Review
Chemistry, Multidisciplinary
Narayan Sinha, Polina Yaltseva, Oliver S. Wenger
Summary: The nephelauxetic effect, which refers to the expansion of d-orbitals as a result of metal-ligand bond covalence, has been recognized for its importance in the design of new photoactive complexes using first-row transition metals. This effect can significantly impact the photophysical properties of 3d metal complexes in solution at room temperature. By exploiting the nephelauxetic effect, red luminescence in Cr-III and Mn-IV complexes has been shifted to the near-infrared spectral region, while charge-transfer excited states in Fe-II and Co-III complexes have been stabilized, improving their properties and application potential.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Vaidish Sumaria, Luan Nguyen, Franklin Feng Tao, Philippe Sautet
Summary: It has been discovered that high CO coverage triggers the restructuring of Pt catalysts, forming atomic protrusions with low-coordination Pt atoms and sub-nano islands on the terraces. Machine-learning-accelerated first-principles atomistic simulations enable exploration of tens of thousands of configurations for CO-covered restructuring catalyst. These studies provide a new avenue for achieving atomic-scale understanding of the structural dynamics of more complex metal nanoparticle catalysts under reaction conditions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Nanoscience & Nanotechnology
Qiankun Hou, Kang Liu, Walid Al-Maksoud, Yuchang Huang, De Ding, Yongpeng Lei, Yi Zhang, Bin Lin, Lirong Zheng, Min Liu, Jean-Marie Basset, Yin Chen
Summary: Nonprecious-metal heterogeneous catalysts with atomically dispersed active sites have shown high activity and selectivity in various reactions, but their rational design and large-scale synthesis pose a significant challenge. Current approaches involve high temperatures and tedious procedures. In this study, a straightforward and scalable strategy was demonstrated for synthesizing atomically dispersed Ni electrocatalysts in a large quantity with high yield, using two simple steps under mild conditions. The resulting catalyst exhibits excellent catalytic performance in both oxygen evolution and reduction reactions, with tunable activity, high reproducibility, and stability. The strategy provides a practical and green method for the industrial manufacturing of nonprecious-metal single-site catalysts with predictable structures.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Dongfang Cheng, Ziyang Wei, Zisheng Zhang, Peter Broekmann, Anastassia N. Alexandrova, Philippe Sautet
Summary: The dynamic restructuring of Cu surfaces in electroreduction conditions was investigated using first-principles calculations and operando electrochemical scanning tunneling microscopy experiments. The restructuring of Cu(111) in acidic electrolyte was found to be potential- and pH-dependent. The strong adsorption of H atoms on the surface induced the formation of Cu adatoms, creating highly active sites for the hydrogen evolution reaction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Nina M. M. Sackers, Julia Nikodemus, Regina Palkovits, Philippe Sautet, Peter J. C. Hausoul
Summary: Despite previous kinetic studies, the mechanism of polyol hydrogenolysis on a Ru catalyst surface remains unclear. To gain insight into the mechanism, decomposition of methanol was investigated using a Ru/C catalyst and periodic DFT calculations on a Ru(0001) model surface. The results suggest that the surface is likely covered by hydrogen adsorbates during the experiments. On a clean Ru surface, a lower overall activation barrier is observed when fewer dehydrogenation steps occur before C-O bond cleavage in the substrate methanol. Transferring these findings to a hydrogen-saturated Ru surface, the pathway involving CH2O O-H formation and subsequent C-O cleavage is found to be the most favorable. This study highlights the significant influence of surface coverage on the activation barrier.
Article
Engineering, Chemical
Yuhang Yu, Sean-Thomas B. Lundin, Keisuke Obata, S. Mani Sarathy, Kazuhiro Takanabe
Summary: A comprehensive microkinetic mechanism for the oxidative coupling of methane (OCM) was developed and verified using a La2O3-CeO2 catalyst. The mechanism accurately predicted the temperature and pressure dependencies of the reaction, providing guidance for achieving high C2-3 yields.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Huihang Qiu, Keisuke Obata, Zhicheng Yuan, Takeshi Nishimoto, Yaerim Lee, Keisuke Nagato, Ikuya Kinefuchi, Junichiro Shiomi, Kazuhiro Takanabe
Summary: The green hydrogen economy is important for carbon neutrality, but industrial-scale water electrolysis needs improvement in efficiency, operation costs, and capital costs. A detailed understanding of bubble behavior in water electrolyzers is necessary to control bubbles. This study investigates how electrolyte properties affect bubble detachment sizes and establishes a quantitative relationship to regulate bubble management through electrolyte engineering.
Article
Chemistry, Physical
Junjie Shi, Hio Tong Ngan, Philippe Sautet, Jason F. F. Weaver
Summary: Dilute Ti-Cu(111) alloys are highly selective for converting ethanol to ethylene. The presence of Ti ensembles on the Cu(111) surface promotes ethanol deoxygenation and enhances the production of gaseous C2H4 and H-2. The Ti ensemble size and the adsorbed O atom released during C-O cleavage significantly influence the reaction selectivity and stability.
Article
Chemistry, Multidisciplinary
Hiroki Komiya, Keisuke Obata, Melody Wada, Takeshi Nishimoto, Kazuhiro Takanabe
Summary: Developing highly active electrocatalysts and conductive electrolytescan improve water-splitting efficiency in the presence of chloride ions. This study introduces a new electrolyte engineering approach using a Cl--containing borate/carbonate mixed buffer electrolyte, which enhances conductivity and achieves a competitive value compared to 30 wt % KOH. The optimized performances for HER and OER are achieved by tuning the concentration of cations and operating pH, resulting in a stable zero-gap cell with high faradaic efficiency for seawater splitting.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Chemistry, Physical
Tomohiro Higashi, Hiroshi Nishiyama, Yuriy Pihosh, Kaisei Wakishima, Yudai Kawase, Yutaka Sasaki, Akira Nagaoka, Kenji Yoshino, Kazuhiro Takanabe, Kazunari Domen
Summary: The self-conductivity of tantalum nitride (Ta3N5) thin film-based semitransparent photoanodes can enhance the current in the photoelectrochemical oxygen evolution reaction (PEC OER) without a conducting substrate. By modifying the surface with NiFeOx-electrocatalyst, an optimized Ta3N5 thin film directly fabricated on a transparent insulating quartz substrate achieved a photocurrent density of about 5.9 ± 0.1 mA cm-2 at 1.23 V vs. the reversible hydrogen electrode under simulated AM 1.5G solar illumination. The relationship between the PEC OER performance of NiFeOx-modified Ta3N5 photoanodes and the electrical properties of Ta3N5 thin films was investigated using Hall effect measurements.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Nina M. Sackers, Andree Iemhoff, Philippe Sautet, Regina Palkovits
Summary: Computational methods were used to investigate well-defined and characterized isolated Ir sites anchored on a covalent triazine framework (CTF) as a showcase for experimentally accessible single-site catalysts. The resting states of the catalyst species after immobilization and after reduction at 400 ? were identified, and they were found not to be the catalytically active species but rather pre-catalysts for the dehydrogenation of formic acid.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Haruka Komada, Keisuke Obata, Duanxing Li, S. Mani Sarathy, Kazuhiro Takanabe
Summary: In this study, a two-stage reactor was used to investigate the successive reactions of oxidative coupling of methane (OCM) products. Homogeneous and heterogeneous gas phase reactions of OCM products on catalysts and supports were systematically investigated. Dehydrogenation and condensation of OCM products were observed in the gas phase, while steam reforming and water gas shift reactions led to the loss of C-2 yield. A design guideline for OCM reactors was proposed based on the findings.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Xiaofei Lu, Tatsuya Shinagawa, Kazuhiro Takanabe
Summary: In addition to the identity of the electrocatalyst materials, the catalytic performance is influenced by the local steady-state environment perturbed by reaction conditions, pressure, and temperature, as well as the operating current density. Strategies developed at low current densities cannot be directly applied to achieve high electrocatalytic performance. This study analyzed the microkinetics of CO electroreduction over high-surface-area Cu-based electrocatalysts, establishing rate expressions and interpreting reaction pathways using Tafel analysis, kinetic isotope effects, and temperature and pressure dependence measurements. The findings revealed the optimal operating conditions for maximizing the performance of specific products.
Article
Chemistry, Multidisciplinary
Simran Kumari, Anastassia N. Alexandrova, Philippe Sautet
Summary: In this study, the nature of zirconia on a copper inverse catalyst under CO2 hydrogenation to methanol conditions was comprehensively investigated using density functional theory calculations and the Grand Canonical Basin Hopping method. The research revealed significant changes in the active site induced by various reaction parameters, and suggested that the active site can be considered as a statistical ensemble of diverse structures.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Giyeong Son, Yichen Li, Anna V. Shneidman, Jae Hyo Han, Michael Aizenberg, Philippe Sautet, Joanna Aizenberg
Summary: Various materials have been developed to extend the function of light-absorbing devices to low-light or nighttime conditions. This study found that crystal surface engineering can be used as a powerful tool to optimize materials for electron storage.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Lujain Alrais, Walid Al Maksoud, Baraa Werghi, Anissa Bendjeriou-Sedjerari, Edy Abou-Hamad, Mohamed N. Hedhili, Jean-Marie Basset
Summary: The synthesis of heterogeneous Ti(iv)-based catalysts for ethylene polymerization according to the concepts of surface organometallic chemistry is described. These catalysts utilize a unique silica support with a 3D fibrous morphology and an aluminum-bound hydroxyl group. The combination of morphological and electronic properties of the support leads to enhanced catalytic performance in ethylene polymerization, resulting in the formation of high-density polyethylene.
CHEMICAL COMMUNICATIONS
(2023)
