Article
Chemistry, Physical
Daniele Giusi, Matteo Miceli, Chiara Genovese, Gabriele Centi, Siglinda Perathoner, Claudio Ampelli
Summary: Copper oxide-based gas-diffusion electrodes (CuxO/GDEs) were studied for CO2 electrocatalytic reduction in presence and absence of liquid electrolyte (liquid- and gas-phase operations). The catalytic behavior and selectivity paths were found to be significantly influenced by the choice of liquid or gas-phase operations. Electrochemical impedance spectroscopy (EIS) was demonstrated to be a strategic tool for optimizing performance beyond the properties of the electrocatalysts themselves.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Article
Chemistry, Physical
Tatyana Reshetenko, Madeleine Odgaard, Guenter Randolf, Kenta K. Ohtaki, John P. Bradley, Barr Zulevi, Xiang Lyu, David A. Cullen, Charl J. Jafta, Alexey Serov, Andrei Kulikovsky
Summary: In this study, a cathodic catalysts layer (CCL) design was achieved using a catalyst coated membrane approach with Platinum Group Metal-free (PGM-free) electrocatalysts. Three different Fe-Mn-N-C compounds were synthesized and characterized, and their electrochemical properties were evaluated. It was found that the CCLs exhibited high proton conductivity and predominantly exhibited a 4e- oxygen reduction reaction mechanism.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Article
Electrochemistry
Andrei Kulikovsky
Summary: A model for PEMFC cathode impedance is developed, and the transient response of catalyst layer proton conductivity to cell current density variation is analyzed. The results show that this transient conductivity leads to the formation of a low-frequency inductive loop in the Nyquist spectrum.
ELECTROCHEMISTRY COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Jagoda Urban-Klaehn, Clarita Y. Regalado Vera, Radoslaw Zaleski, Hanping Ding, Hongmei Luo, Dong Ding
Summary: The study focused on defect chemistry of doped BaZrO3 proton conductors, and its findings have significant implications for proton conductivity. Using positron annihilation lifetime spectroscopy, the researchers showed that yttrium doping increased the trapping rate of positrons, while scandium doping did not have the same effect. Additionally, low-temperature hydration significantly inhibited positron trapping in the samples.
SOLID STATE IONICS
(2023)
Article
Electrochemistry
William Ait-Idir, Peizhe Wu, Ricardo Sgarbi, Quentin Labarde, Salah Touhami, Meriem Daoudi, Assma El Kaddouri, Jean-Christophe Perrin, Jerome Dillet, Clemence Marty, Fabrice Micoud, Marian Chatenet, Olivier Lottin, Julia Mainka
Summary: In PEM fuel cells, oxygen diffusion is influenced by both the gas diffusion layer and the cathode catalyst layer. Experimental data shows that the low-frequency diffusion impedance is mainly related to the gas diffusion layer, while the high-frequency impedance is primarily affected by the ionomer film in the cathode catalyst layer. Therefore, the appropriate equivalent electrical circuit is the series connection of the Kulikovsky diffusion impedance and the ORR kinetics circuit.
ELECTROCHIMICA ACTA
(2023)
Article
Chemistry, Physical
J. A. Martinez-Gonzalez, H. Cavaye, J. D. McGettrick, P. Meredith, K. A. Motovilov, A. B. Mostert
Summary: The research on electrically functional biomaterials has found that the state of hydration and water morphology can greatly affect the conductivity of materials relying on ionic or proton transport. A study on eumelanin revealed the dominance of interfacial water in the hydrated state, with no bulk water present, and also detected potential signatures for proton cations within the system. These new findings raise questions about ionic charge transport mechanisms in hydrated bioelectronics materials.
Article
Spectroscopy
Kazuki Inoue, Masanari Okuno
Summary: Hyper-Raman spectra of concentrated hydrochloric acid solutions were reported for the first time. The spectra reflected the presence of chloride anions solvated in water. Unlike infrared spectroscopy, the Hyper-Raman spectra were insensitive to excess protons in water and did not show any signature of a proton continuum or shoulders on the bending mode of H2O. Additionally, a sharp Hyper-Raman signal at around 500 cm(-1) was observed in the 532 nm excited spectra, indicating a photochemical reaction.
JOURNAL OF RAMAN SPECTROSCOPY
(2022)
Article
Chemistry, Analytical
Eric Ruzicka, Perry Pellechia, Brian C. Benicewicz
Summary: Diffusion-ordered spectroscopy (DOSY) 1H nuclear magnetic resonance (NMR) is a powerful tool for characterizing the molecular weights of polymers. Compared to common techniques, DOSY is faster and more cost-effective, and does not require purified samples. The study emphasizes the importance of proper preparation in generating calibration curves, including selecting the correct pulse sequence, optimizing parameters, and sample preparation. It also highlights the increasing significance of incorporating DOSY NMR into the polymer chemist's toolbox.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Physical
Anantrao Vijay Shirsath, Caroline Bonnet, Stephane Rael, Francois Lapicque
Summary: Electrochemical pressure impedance spectroscopy (EPIS) is used to differentiate gas and liquid transport/transfer phenomena in electrochemical cells. This study investigates EPIS impedance in a membrane fuel cell under predominant gas transport control, with little presence of liquid water. Results show that operating the fuel cell with pure oxygen allows observation of gas convection, while oxygen dilution leads to diffusion phenomena. The presence of liquid water and poor management of it worsen gas transport situation in the porous layers.
JOURNAL OF POWER SOURCES
(2022)
Article
Thermodynamics
Yi Li, Fang Yuan, Rengang Weng, Fang Xi, Wei Liu
Summary: The porosity distribution in the gas diffusion layer significantly impacts cell performance. An optimized three-dimensional nonuniform porosity distribution is proposed to increase current density and power density. Different design schemes are evaluated, with the optimized porosity distribution showing the best performance.
Article
Electrochemistry
Elisabetta Achilli, Simone Minelli, Irene Casale, Xiufang He, Giovanni Agostini, Giorgio Spinolo, Paolo Ghigna, Alessandro Minguzzi, Alberto Vertova
Summary: Charge transfer reactions in electrodeposited iridium oxide films (EIROF) are investigated using operando energy dispersive X-ray absorption spectroscopy (EDXAS). The experimental results provide important information about the reaction rates and rate-determining steps. In addition, the diffusion coefficient of H+ ions within the catalyst layer is determined and compared to data obtained by electrochemical impedance spectroscopy (EIS).
ELECTROCHIMICA ACTA
(2023)
Article
Chemistry, Physical
Biswajit Biswas, Prashant Chandra Singh
Summary: The hydrated proton at membrane interfaces is crucial in the bioenergetic process of organisms. By measuring vibrational sum frequency generated spectra of lipids in the presence of acids, the signature of the hydrated proton at membrane interfaces has been investigated. The results show that the hydrated proton reshapes the interaction between interfacial water molecules near the lipid interfaces.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Electrochemistry
Andrei Kulikovsky
Summary: By placing an inactive catalyst layer between two membranes in a proton exchange membrane fuel cell, a model is developed to analyze the impedance characteristics of the catalyst layer, allowing for estimation of its proton and electron conductivity, as well as capacitance, without the need for complicated curve fitting.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2021)
Article
Chemistry, Physical
Xingzi Yu, Caizhi Zhang, Mengxiao Li, Bin Chen, Min Fan, Xinfa Sheng, Fangping Ma
Summary: This paper analyzes the self-regulating capability of the open-cathode PEMFC stack when its cooling fan operates under different voltages. The results show that the stack achieves better self-regulation when the fan operates at 8.5V in both blow mode and suction mode. The stack can adjust activation resistance and ohmic resistance to realize self-regulating function, with the cathode activation resistance playing a dominant role.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Cristian E. Botez, Israel Martinez, Alex D. Price
Summary: Using powder X-ray diffraction and AC impedance spectroscopy, it was found that the superprotonic CsH2PO4 (CDP) phase can be stabilized at 250 degrees C when sealed in dry air or inert gasses. The proton conductivity of CDP remains constant for at least 10 hours under these conditions. However, removing the gas from the chamber leads to a significant drop in proton conductivity.
Article
Chemistry, Physical
Swati Gahlot, Vaibhav Kulshrestha
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2020)
Article
Environmental Sciences
Savan K. Raj, Vikrant Yadav, Gopala R. Bhadu, Rajesh Patidar, Manoj Kumar, Vaibhav Kulshrestha
Summary: The synthesized GQDs show high fluorescence and are suitable for detecting heavy metal ions, with a stable intensity for several months. They also exhibit selective recognition of Fe3+, Pb2+ and Cr3+ ions, making them a promising material for heavy metal ion sensing applications.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Editorial Material
Chemistry, Physical
Vinod K. Shahi, Vaibhav Kulshrestha
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2020)
Article
Chemistry, Physical
Nehal H. Rathod, Vikrant Yadav, Abhishek Rajput, Jeet Sharma, D. K. Shukla, Vaibhav Kulshrestha
COLLOID AND INTERFACE SCIENCE COMMUNICATIONS
(2020)
Article
Chemistry, Physical
Vikrant Yadav, Nagaraju Niluroutu, Santoshkumar D. Bhat, Vaibhav Kulshrestha
ACS APPLIED ENERGY MATERIALS
(2020)
Article
Engineering, Chemical
Vikrant Yadav, Savan K. Raj, Nehal H. Rathod, Vaibhav Kulshrestha
JOURNAL OF MEMBRANE SCIENCE
(2020)
Article
Chemistry, Multidisciplinary
Nehal H. Rathod, Jeet Sharma, Sayan K. Raj, Vikrant Yadav, Abhishek Rajput, Vaibhav Kulshrestha
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2020)
Article
Chemistry, Physical
Abhishek Rajput, Savan K. Raj, Oksana V. Lebedeva, Alexandra N. Chesnokova, Tatiana V. Raskulova, Vaibhav Kulshrestha
Summary: Functionalized carbon dots were investigated as potential organic fillers for sulfonated poly (ether sulfone) based composite cation exchange membranes to enhance membrane performance. The addition of sulfonated carbon dots improved physicochemical and electrochemical properties of the composite membranes, resulting in increased ionic conductivity and ion exchange capacity. The composite membranes showed a significant reduction in power consumption during salt removal from brackish water in comparison to membranes without the filler material.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Engineering, Chemical
Prem P. Sharma, Vikrant Yadav, Abhishek Rajput, Hariom Gupta, Hitesh Saravaia, Vaibhav Kulshrestha
Article
Chemistry, Physical
Anmol Shahi, Chandresh Dwivedi, S. D. Manjare, Vaibhav Kulshrestha
Summary: By preparing sulphonated poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP) and sulphonated graphene oxide (SGO) composite stable and efficient polymer electrolyte membrane, not only the electrolysis performance of HI can be improved, but also simultaneous production of H2 and I2 can be achieved.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Engineering, Chemical
Vikrant Yadav, Nehal H. Rathod, Jeet Sharma, Vaibhav Kulshrestha
Summary: This article introduces the synthesis and analysis of poly(vinylidene fluoride-co-hexafluompropylene) based anion exchange membranes for electrodialysis, demonstrating their notable electrochemical properties for brackish water desalination. TEM and AFM imaging provide insights into the membrane's structure and properties, contributing to the optimization of AEMs for efficient electrodialysis applications.
JOURNAL OF MEMBRANE SCIENCE
(2021)
Article
Chemistry, Physical
Abhishek Rajput, Savan K. Raj, Jeet Sharma, Nehal H. Rathod, P. D. Maru, Vaibhav Kulshrestha
Summary: The sulfonated poly ether ether ketone (SPEEK) based functionalized hexagonal boron nitride (SBN) composite cation exchange membranes showed improved ion conductivity and ion exchange capacity for water desalination. Incorporation of SBN not only enhanced membrane performance but also increased membrane stability.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Engineering, Environmental
Jeet Sharma, S. K. Misra, Vaibhav Kulshrestha
Summary: This study introduces a novel anion exchange membrane for acid recovery via diffusion dialysis, showing good water uptake and ion exchange capacity for efficient recovery of acids from Cl-1, NO3, and SO42- ions. The membranes exhibit high proton diffusion coefficients and enhanced separation factor values, leading to efficient recovery efficiencies varying with different acids.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Abhishek Rajput, Prem P. Sharma, Savan K. Raj, Jyoti Kumari, Mangal S. Rathore, Vaibhav Kulshrestha
Summary: The study demonstrates the use of ion-exchange membranes synthesized through free-radical polymerization for efficient electrodialysis desalination of brackish water. The membranes show improved desalination performance with slight temperature increment, and cost-effective production methods were identified.
MATERIALS TODAY CHEMISTRY
(2021)
Article
Engineering, Chemical
Vikrant Yadav, Abhishek Rajput, Vaibhav Kulshrestha
JOURNAL OF MEMBRANE SCIENCE
(2020)