Article
Chemistry, Physical
Camilla F. S. Codeco, Alexander Yu Klyushin, Emilia A. Carbonio, Axel Knop-Gericke, Robert Schloegl, Travis Jones, Tulio C. R. Rocha
Summary: Adsorbed hydroxyl is a key intermediate in many catalytic reactions and electrochemical processes, particularly on noble metal surfaces. In this study, a fully hydroxylated surface phase in equilibrium with water and oxygen in the gas phase under near ambient conditions was prepared from a well-defined oxygen covered Ag(110) surface with O-p(2 x 1) reconstruction. In situ soft X-ray spectroscopy and density functional theory showed distinct modifications in the electronic structure of the adsorbate layer upon hydroxylation.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Sebastiano Romi, Samuele Fanetti, Frederico Alabarse, Antonio M. Mio, Julien Haines, Roberto Bini
Summary: Saturated carbon nanothreads have been successfully synthesized, and their mechanical properties and reactivity have been characterized. The synthesis of double nanothreads with tunable optical properties and band gap has been demonstrated. The study also provides insights into the threshold conditions, kinetics, and structure-reaction relationship.
Article
Nanoscience & Nanotechnology
Ida Kallquist, Tove Ericson, Fredrik Lindgren, Heyin Chen, Andrey Shavorskiy, Julia Maibach, Maria Hahlin
Summary: This article presents a method for measuring potential differences at the solid/liquid interface in a battery using operando ambient pressure photoelectron spectroscopy (APPES) and proposes a model. By using a Li4Ti5O12 composite as the working electrode, the study demonstrates that the shifts in kinetic energy measured by APPES can be used to study electrochemical reactions.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Yaman Goksel, Elodie Dumont, Roman Slipets, Sriram T. Rajendran, Sevde Sarikaya, Lasse H. E. Thamdrup, Kjeld Schmiegelow, Tomas Rindzevicius, Kinga Zor, Anja Boisen
Summary: Therapeutic drug monitoring (TDM) is crucial for optimizing drug dosing and avoiding adverse effects. In this study, an electrochemically assisted surface-enhanced Raman spectroscopy (SERS) method and a benchtop Raman detection system were developed for the detection of methotrexate (MTX). The method showed promising results and can be used in resource-limited environments.
Article
Chemistry, Physical
Robert H. Temperton, Anurag Kawde, Axl Eriksson, Weijia Wang, Esko Kokkonen, Rosemary Jones, Sabrina Maria Gericke, Suyun Zhu, Wilson Quevedo, Robert Seidel, Joachim Schnadt, Andrey Shavorskiy, Petter Persson, Jens Uhlig
Summary: This paper presents a proof-of-principle study on the oxidation and reduction reactions of a model organometallic complex, iron hexacyanide, in an aqueous solution using Ambient Pressure X-ray Photoelectron Spectroscopy (APXPS). The study demonstrates that controlled redox reactions can occur on the working electrode's electrochemically active liquid meniscuses, which were observed using APXPS. The paper also includes a detailed discussion on critical experimental considerations as guidance for similar experiments.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Chathura de Alwis, Mikhail Trought, Ethan J. Crumlin, Slavomir Nemsak, Kathryn A. Perrine
Summary: Iron plays a crucial role in natural processes and undergoes various reactions that result in corrosion films. This study investigates the initial stages of iron surface corrosion using spectroscopy techniques. The presence of oxygen and water vapor enhances the growth of carbonates, while chloride ions migrate into the interface. Water has a significant effect on carbonate growth at low pressures, while both water and oxygen increase carbonate growth at near ambient pressures. These findings have implications for understanding catalytic and redox chemistry on iron surfaces.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Jason E. Colley, Dylan S. Orr, Michael A. Duncan
Summary: Gas-phase ion-molecule complexes of silver cation with benzene or toluene are generated and photodissociated via laser vaporization. The photodissociation process produces the organic cation as the only fragment via a metal-to-ligand charge transfer process. The electronic spectra of the charge-transfer process and other transitions are examined using tunable UV-visible lasers.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Cong Liu, Xianping Zhang, Chiheng Dong, Dongliang Wang, Chao Yao, He Huang, Zhongtang Xu, Satoshi Awaji, Yanwei Ma
Summary: In the field of iron-based superconductors (IBS), the multi-filament Cu/Ag composite sheathed Ba-122 tape stands out for its excellent properties, making it particularly attractive for industrial high-field applications. By utilizing a cost-effective and scalable method called ambient pressure sintering, a high transport critical current density (Jc) of 4.5 x 104 A cm-2 at 4.2 K and 10 T was achieved for 7-filament Cu/Ag sheathed Ba-122 tapes, with an engineering critical current density (Je) reaching 104 A cm-2. The adoption of an optimized powder-in-tube (PIT) method successfully overcame the challenges of ambient pressure sintering, resulting in high-density superconducting core and grain alignment. Improvements in the manufacturing process, such as drawing without intermediate annealing and rolling from larger initial diameter to thinner tapes, contributed to high grain connectivity and good c-axis texture, which greatly influenced the high Jc performance. This research demonstrates the viability of the ambient pressure sintering process for the fabrication of long-length multifilamentary Cu/Ag composite sheathed IBS tapes with high Jc, making them suitable for practical high-field applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Jiayi Tang, Okkyun Seo, David S. Rivera Rocabado, Takanori Koitaya, Susumu Yamamoto, Yusuke Nanba, Chulho Song, Jaemyung Kim, Akitaka Yoshigoe, Michihisa Koyama, Shun Dekura, Hirokazu Kobayashi, Hiroshi Kitagawa, Osami Sakata, Iwao Matsuda, Jun Yoshinobu
Summary: The absorption and diffusion of hydrogen in cube-shaped palladium nanoparticles were investigated using AP-XPS and DFT calculations. The study found a size dependence in the subsurface hydrogen absorption and proposed a model for the interaction between hydrogen and palladium nanoparticles.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
Wanwan Wang, Yu Wang, Chia-Hsin Wang, Yaw-Wen Yang, Yi-Chun Lu
Summary: Direct probing of metal-oxygen chemistry at the solid/liquid interface is crucial for understanding the reaction mechanism of metal-air batteries. This study, using APXPS, demonstrates in situ probing of potassium oxygen reduction/evolution reaction in ionic liquid-based air batteries, revealing new reaction pathways and root causes of irreversible cell chemistry. The formation and oxidation of K2O2 trigger irreversible cell chemistry, contributing to capacity decay in K-O-2 batteries, and impurities in air such as H2O and CO2 reduce chemical reversibility of ORR and OER.
ENERGY STORAGE MATERIALS
(2021)
Article
Physics, Applied
Matteo Amati, Luca Gregoratti, Patrick Zeller, Mark Greiner, Mattia Scardamaglia, Benjamin Junker, Tamara Russ, Udo Weimar, Nicolae Barsan, Marco Favaro, Abdulaziz Alharbi, Ingvild J. T. Jensen, Ayaz Ali, Branson D. Belle
Summary: Near ambient pressure scanning photoelectron microscopy combines high resolution microscopy with the capability of chemical analysis under high gas pressure conditions, making it valuable for fundamental and applied research such as oxidation reactivity and gas sensitivity.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Chemistry, Physical
Ariful Haque, Radhamadhab Das, M. Vasundhara, Debamalya Ghosh, Arup Gayen, Partha Mahata, Asish K. Kundu, Md. Motin Seikh
Summary: In this study, very low Ti-content quadruple perovskites were successfully synthesized for the first time using the sol-gel process. Characterization using various techniques confirmed the crystal structure and chemical homogeneity of the samples, with magnetic properties showing a significant dependence on Ti content. The low temperature re-entrant spin glass state was attributed to the mixed occupancy of Cu2+ and Mn3+ ions in the A-site.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Spectroscopy
F. O. L. Johansson, T. Leitner, I. Bidermane, A. Born, A. Foehlisch, S. Svensson, N. Martensson, A. Lindblad
Summary: The oxygen on Ag(111) system was investigated using Auger electron-photoelectron coincidence spectroscopy (APECS). The coincidence spectra between O 1s core level photoelectrons and O KLL Auger electrons, as well as Ag(3)d/AgM4,5NN coincidences, revealed the characteristics of molecular oxygen and chemisorbed oxygen. The setup and data acquisition and treatment procedure of the electron-electron coincidence spectrometer (CoESCA) used in this study were also described. The findings are significant for the catalytic ethylene oxidation.
JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA
(2022)
Article
Chemistry, Physical
Rachel Martin, Christopher J. Lee, Vikram Mehar, Minkyu Kim, Aravind Asthagiri, Jason F. Weaver
Summary: The catalytic oxidation of CH4 over IrO2 (110) films on Ir(100) was studied using AP-XPS. The results showed that IrO2 (110) can efficiently catalyze the oxidation of CH4 over a wide range of temperatures and mixture compositions. OH groups and oxidized C-containing species formed on the IrO2 (110) surfaces during CH4 oxidation, indicating that the dissociative adsorption of O-2 is more favorable than CH4 activation. Extensively oxidized surface species with a CHyO2 stoichiometry preferentially formed under all reaction conditions studied. This study provides quantitative information for validating first-principles models and optimizing the performance of IrO2 catalysts for CH4 oxidation.
Article
Chemistry, Physical
Fumihiko Ozaki, Shunsuke Tanaka, Younghyun Choi, Wataru Osada, Kozo Mukai, Mitsuaki Kawamura, Masahiro Fukuda, Masafumi Horio, Takanori Koitaya, Susumu Yamamoto, Iwao Matsuda, Taisuke Ozaki, Jun Yoshinobu
Summary: Sulfur vacancies on an MoS2 basal plane significantly affect device performance and catalytic activity. This study investigates the electronic states of sulfur vacancies using AP-XPS and density functional theory calculations. The results provide insights into the changes in electronic states induced by sulfur vacancy formation and offer guidance for sulfur vacancy engineering.
Article
Chemistry, Multidisciplinary
Himan Dev Singh, Shyamapada Nandi, Debanjan Chakraborty, Kirandeep Singh, Chathakudath P. Vinod, Ramanathan Vaidhyanathan
Summary: Coordination flexibility assisted porosity was introduced into an Iron-isonicotinate metal-organic framework, which exhibited CO2-specific gate opening behavior and could be tuned by temperature and pressure. The framework selectively adsorbed CO2 through gate opening phenomenon. Isonicotinate bound to the Fe3+ center weakly, enabling the gate to open under CO2 pressure and significantly increase CO2 uptake. This framework showed improved selectivity for CO2/N-2 and CO2/CH4 gas separation.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
Article
Chemistry, Applied
Paresh A. Kamble, C. P. Vinod, Virendra K. Rathod, Mannepalli Lakshmi Kantam
Summary: A series of Ni/Organoclay catalysts with different Nickel loadings were prepared by the wet impregnation method and used for the catalytic hydrogenation of levulinic acid (LA) to gamma-valerolactone (GVL). Optimum reaction conditions were determined, and Ni/Organoclay with 30% Nickel loading exhibited excellent conversion and selectivity. Various characterization techniques were used, showing that the pre-treatment of bentonite with surfactant improved the properties of the catalyst.
Article
Multidisciplinary Sciences
Sanchayita Mukhopadhyay, Mruthyunjayachari Chattanahalli Devendrachari, Sandeep C. Kanade, Chathakudath Prabhakaran Vinod, Harish Makri Nimbegondi Kotresh, Musthafa Ottakam Thotiyl
Summary: This study investigates the role of ligand isomerism in modulating the mechanisms and kinetics of charge/discharge chemistry in an aqueous metal-air battery. It finds that the alpha-NO2 isomer decreases the rate of oxygen reduction and oxygen evolution reactions, while the beta-NO2 isomer enhances these reactions. When integrated into a Zn-air battery, the beta-NO2 isomer significantly reduces overpotential and increases round-trip efficiency.
Article
Chemistry, Multidisciplinary
Kousik Das, Risov Das, Mohd Riyaz, Arko Parui, Debabrata Bagchi, Ashutosh Kumar Singh, Abhishek Kumar Singh, Chathakudath P. Vinod, Sebastian C. Peter
Summary: Obtaining multi-carbon products from CO2 photoreduction is a challenging catalytic process, but complex design of multicomponent interfaces can lead to unpredictable changes in the interfacial chemical environment. This study presents a novel photocatalyst, Bi19S27Cl3, which selectively converts CO2 to ethanol under visible light. Structural analysis reveals the presence of charge polarized bismuth centers in Bi19S27Cl3, which enhance the separation efficiency of photogenerated electron-hole pairs. In addition, these polarized centers promote the adsorption of CO* intermediates and accelerate the rate determining C-C coupling step.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Subhajit Chakraborty, Risov Das, Mohd Riyaz, Kousik Das, Ashutosh Kumar Singh, Debabrata Bagchi, Chathakudath P. P. Vinod, Sebastian C. C. Peter
Summary: We propose a surface reconstruction-induced C-C coupling reaction in which CO2 is converted into ethylene. The wurtzite phase of CuGaS2 undergoes in situ surface reconstruction, forming a thin CuO layer on the pristine catalyst, which facilitates selective conversion of CO2 to ethylene (C2H4). Under illumination, the catalyst efficiently converts CO2 to C2H4 with 75.1% selectivity (92.7% selectivity in terms of R-electron) and a 20.6 μmol g(-1) h(-1) evolution rate. Spectroscopic and microscopic studies, supported by theoretical analysis, reveal that operando-generated Cu2+ and existing Cu+ function as an anchor for the generated *CO, thereby facilitating C-C coupling. This study demonstrates the importance of strain-induced in situ surface reconstruction in modulating the oxidation state of Cu and controlling the CO2 reduction reaction pathway for selective ethylene formation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Inorganic & Nuclear
Inderjeet Chauhan, Kshirodra Kumar Patra, Himanshu Bajpai, Nitin B. Mhamane, Kranti N. Salgaonkar, Chinnakonda S. Gopinath
Summary: Co-doping into the BiVO4 lattice enhances the kinetics and sustainability of chlorine evolution reaction (CER), leading to selective CER at a low operating potential. The best-performing photoanode, with 0.05 mol% Co doping, selectively produces active chlorine with high faradaic efficiency and demonstrates stability for up to 20 hours.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Physical
Raj Sekhar Roy, Sanjit Mondal, Samita Mishra, Maqsuma Banoo, Lipipuspa Sahoo, Amit Kumar, C. P. Vinod, Arijit K. De, Ujjal K. Gautam
Summary: A strategy for covalently linking adjacent layers of g-C3N4 using diethylene glycol as a precursor is introduced to achieve a high surface area in a one-step process. The introduced linkers provide mechanical stability and increase the efficiency of photocatalytic water-splitting.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Engineering, Chemical
Rakhi Vishwakarma, Chathakudath P. Vinod, Virendra Rathod, Mannepalli Lakshmi Kantam
Summary: The Wadsworth-Emmons reaction was successfully conducted using the fluorapatite (FAP) catalyst, resulting in 100% conversion and 80% selectivity of α,β-unsaturated ester from the reaction of 2-methoxybenzaldehyde and triethylphosphonoacetate. The kinetic model was validated at different temperatures and the absence of mass transfer resistance was confirmed. Various factors such as catalysts, temperature, catalyst loading, solvent, mole ratio, and stirring speed were investigated. The FAP catalyst exhibited stability up to three cycles without any loss in activity as characterized by multiple methods.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Rakhi Vishwakarma, C. P. Vinod, Virendra K. Rathod, Mannepalli Lakshmi Kantam
Summary: The synthesis of N,N-diphenylformamide from N-benzylideneaniline and urea hydrogen peroxide using a ZnHAP catalyst was investigated. The catalyst exhibited the highest activity with 91% conversion and 40% selectivity at 130 degrees C in 2 hours. A kinetic model was validated and the absence of mass transfer resistance was confirmed. Various factors including catalyst type, loading, temperature, mole-ratio, and stirring speed were studied. The synthesized ZnHAP catalyst was characterized and found to be stable for three cycles without loss in activity.
Article
Engineering, Environmental
Ravi Ranjan, Jyoti Tekawadia, Ruchi Jain, Nitin B. Mhamane, Thirumalaiswamy Raja, Chinnakonda S. Gopinath
Summary: The main challenges in heterogeneous catalytic CO2 reduction are to minimize H2 consumption while maximizing CO2 conversion, and to enhance CO selectivity while reducing methane production. Co3O4 spinel has been found to be a potential catalyst with high CO selectivity at atmospheric pressure. The current work demonstrates sustainable CO2 conversion to 100% CO selectivity using Co3O4 nanocubes, with increased CO selectivity and yield at the cost of methane.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Nitin B. B. Mhamane, Suresh Panchal, Sadhu K. K. Kolekar, Ravi Ranjan, Kranti N. N. Salgaonkar, Anand S. S. Burange, Naresh Nalajala, Suwarna Datar, Chinnakonda S. S. Gopinath
Summary: The present study demonstrates the effect of temperature-dependent surface modification (SM) treatment on Pd-TiO2 catalysts, which broadens the catalysis regime by shifting the onset of CO oxidation activity to lower temperatures. The SM process induces changes in the surface properties, such as work function, surface potential, and catalytic activity. XPS, UPS, and AFM techniques were used to investigate the SMd Pd-TiO2 catalysts, and it was found that diffusion of atomic oxygen into the subsurface layers of Pd led to significant surface modification. The changes in work function (& phi;) were correlated with the observed changes in catalytic activity. Additionally, the surface potential was found to increase linearly with increasing SM temperature up to 523 K. These findings suggest that the work function can serve as a global marker for chemical reactivity.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Kranti N. Salgaonkar, Himanshu Bajpai, Nitin B. Mhamane, Naresh Nalajala, Inderjeet Chauhan, Kavita Thakkar, Kavita Joshi, Chinnakonda S. Gopinath
Summary: The article discusses the research on achieving artificial photosynthesis for liquid fuels with improved solar-to-fuel efficiency. The use of BiVO4 quantum dots integrated with TiO2 showed promising results in terms of charge separation and utilization, leading to a high photon to chemical conversion turn over frequency. The study also demonstrated the scalability and sustainability of the technology.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Kshirodra Kumar Patra, Chinnakonda S. Gopinath
Summary: This study discusses the impact of catalyst material, electrolyte, and gas diffusion electrode on the CO2RR in a gas-fed flow cell. It emphasizes the need for promising catalysts with a partial current density of >= 100 mA cm(-2) and high faradaic efficiency for scale-up requirements. The study also lists additional experimental hurdles and their potential solutions, as well as the best available protocols for data acquisition for catalyst activity evaluation.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Physical
K. Rajendran, Mandeep Sharma, Augustine Jaison, Menon Ankitha, Ankit D. Tiwari, C. P. Vinod, Dinesh Jagadeesan
Summary: Catalytic oxidation using non-noble metal-based catalysts is a promising approach to reduce pollution caused by VOCs in the air. In this study, mesoporous Cu/TiO2 catalysts with different concentrations of Cu2+ were synthesized and characterized. The catalytic activity of Cu/TiO2 in the thermal oxidation of ethylene was investigated, showing higher activity compared to TiO2, especially with 1% Cu doping. The presence of Cu+ and Cu2+ ions, as well as oxygen vacancies, may contribute to the enhanced catalytic performance. Overall, Cu/TiO2 has demonstrated excellent catalytic activity and stability.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Risov Das, Kousik Das, Bitan Ray, Chathakudath P. Vinod, Sebastian C. Peter
Summary: This paper reports a composite photocatalyst composed of nano-sized red phosphorus (RP) and Bi2MoO6 nanoparticles, which can convert CO2 to ethanol. Spectroscopic and experimental evidence demonstrate the crucial role of Bi-Mo dual sites in the reaction process.
ENERGY & ENVIRONMENTAL SCIENCE
(2022)
