Article
Chemistry, Analytical
Michelle Hadad, Nadine Hadad, Alexander G. Zestos
Summary: In this study, a method for measuring cortisol using carbon fiber microelectrodes and fast-scan cyclic voltammetry was developed. This method showed high sensitivity, high spatiotemporal resolution, and biocompatibility, and it was able to detect cortisol stably. Its application will contribute to a better understanding of the physiological importance of cortisol.
Article
Electrochemistry
Chase Stucky, Michael A. Johnson
Summary: In this study, it was found that three different SSRIs significantly decrease the oxidation current of serotonin when using the commonly used Jackson waveform. Coating carbon-fiber microelectrodes with Nafion further reduces the current and increases response times. To address fouling issues, an extended serotonin waveform was used, which alleviated the decrease in current, indicating reduced electrode fouling.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2022)
Review
Chemistry, Analytical
Cailing He, Mengdan Tao, Chenxi Zhang, Yifang He, Wei Xu, Yan Liu, Wanying Zhu
Summary: Dopamine is an essential neurotransmitter in the central nervous system and its abnormal metabolism is related to various diseases. Electrochemical sensing technology, particularly with microelectrodes, is recognized as the most effective method for measuring neurotransmitters in vivo. This article reviews recent applications and research on microelectrodes for dopamine detection in vivo, highlighting the advantages of high sensitivity and spatial resolution.
CRITICAL REVIEWS IN ANALYTICAL CHEMISTRY
(2022)
Article
Materials Science, Multidisciplinary
Xu Chen, Yang Zhang, Yashuai Pang, Haiwu Zheng, Qiwei Jiang
Summary: The flexible porous cotton-carbon fiber cloth (PCC) film shows good electrocatalytic activity and high conductivity. The NiS/PCC electrode performs well in DSSC, with a photoelectric conversion efficiency of 6.80%, surpassing the traditional FTO/Pt electrode. This inexpensive, flexible, and lightweight material has potential for large-scale application.
Review
Chemistry, Physical
Stephane Marinesco
Summary: Chemical transmission between neurosecretory cells is a central biological phenomenon that can be studied using electrochemical techniques. Carbon fiber microelectrodes are commonly used to detect neurotransmitters and can be modified for specific and sensitive in situ neurotransmitter detection, making them an essential tool for analyzing living cells and tissues.
CURRENT OPINION IN ELECTROCHEMISTRY
(2021)
Article
Chemistry, Analytical
Ziyue Sun, Hongli Zhao, Kaicha Chen, Fangfang Zhou, Minbo Lan
Summary: In this study, a carbon fiber microelectrode (CFME) coated with an ERGO-CNT network was used as a substrate to support dendrite PtPd nanoclusters, and an enzyme-free O2 center dot- electrochemical sensor (PtPd@ERGO-CNT-CFME) was prepared based on this strategy. The as-constructed sensor exhibited outstanding detection ability towards O2 center dot-, attributed to the loading and dispersing abilities of the substrate and the electrochemical activity of the dendrite PtPd alloy. The sensor showed a wide-linear range, high sensitivity, and low detection limit, and was successfully applied for O2 center dot- detection in biological samples.
MICROCHEMICAL JOURNAL
(2023)
Article
Chemistry, Physical
Karla Caroline de Freitas Araujo, Emily Cintia Tossi de Araujo Costa, Danyelle Medeiros de Araujo, Elisama V. Santos, Carlos A. Martinez-Huitle, Pollyana Souza Castro
Summary: In the development of electrochemical sensors, carbon micro-structured or micro-materials have been widely used as supports/modifiers to improve the performance of bare electrodes. However, no attempts for electroanalytical determination of caffeine with CF microelectrode have been reported in the literature. Therefore, a homemade CF-microelectrode was fabricated and used to determine caffeine in soft beverage samples.
Article
Engineering, Electrical & Electronic
Alicja Anuszkiewicz, Marcin Franczyk, Dariusz Pysz, Filip Wlodarczyk, Adam Filipkowski, Ryszard Buczynski, Tomasz Osuch
Summary: We have developed a silica-based large mode area fiber with a nanostructured core for use in fiber laser cavities. Our experimental results demonstrate that the fiber operates in single mode with low bending loss. We have also successfully fabricated high reflectivity UV induced fiber Bragg gratings and utilized them in a fiber laser setup. The flexibility of the nanostructuring approach holds promise for the development of passive fiber components that can be matched with any type of active fibers.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Qiang Fu, Jia-Qi Dai, Xin-Yu Huang, Yun-Yun Dai, Yu-Hao Pan, Long-Long Yang, Zhen-Yu Sun, Tai-Min Miao, Meng-Fan Zhou, Lin Zhao, Wei-Jie Zhao, Xu Han, Jun-Peng Lu, Hong-Jun Gao, Xing-Jiang Zhou, Ye-Liang Wang, Zhen-Hua Ni, Wei Ji, Yuan Huang
Summary: The authors present a one-step Ag-assisted method for efficient exfoliation of large-area 2D monolayers with a yield ratio comparable to the Au-enhanced exfoliation method. The rough Ag surface facilitates the generation of surface plasmons, and the strong coupling between 2D semiconductor crystals and the Ag film leads to unique photoluminescence enhancement.
Review
Chemistry, Physical
Xueying Cao, Dongxing Tan, Bari Wulan, K. S. Hui, K. N. Hui, Jintao Zhang
Summary: The electrocatalytic reduction of carbon dioxide into organic fuels and feedstocks is essential for implementing the sustainable carbon cycle. Rational design of advanced electrocatalysts and a deep understanding of reaction mechanisms are crucial for complex reactions. In situ and operando techniques with real-time monitoring provide insight into the dynamic evolution of electrocatalysts' structures.
Article
Biochemistry & Molecular Biology
Guilhem Pignol, Patricia Bassil, Jean-Marie Fontmorin, Didier Floner, Florence Geneste, Philippe Hapiot
Summary: The electrochemical behaviors of carbon fibers from carbon felts were studied using different redox couples. The results showed that the original carbon fiber had different electrochemical reactivities at different sites and the Butler-Volmer law was not suitable to describe the electron transfer kinetics. Oxidation treatment improved the electron transfer kinetics and the analysis revealed the significant influence of convection on the electrochemical response.
Article
Chemistry, Multidisciplinary
Boyu Zhu, Xinru Li, Lihang Zhu, Min Qi, Jiayi Cao, Lin Zhou, Bin Su
Summary: This study investigates the changes in brain glucose levels of early diabetic mice using in vivo electrochemical measurement. The research suggests that diabetes may downregulate the activity of glucose transporter in the brain, leading to a decrease in brain glucose uptake.
Article
Chemistry, Multidisciplinary
Laney C. Kimble, Jack S. Twiddy, Jenna M. Berger, Alexandra G. Forderhase, Gregory S. Mccarty, John Meitzen, Leslie A. Sombers
Summary: This article presents a novel glutamate microbiosensor fabricated on a carbon-fiber microelectrode substrate and coupled with fast-scan cyclic voltammetry (FSCV) for simultaneous quantification of glutamate and dopamine in the brain. The sensor demonstrates high sensitivity, stability, and selectivity, making it a powerful tool for studying neural circuits.
Article
Optics
Zhi Li, Yongguang Xiao, Fu Liu, Xiangyu Yan, Daotong You, Kaiwei Li, Lixi Zeng, Mingshan Zhu, Gaozhi Xiao, Jacques Albert, Tuan Guo
Summary: In this study, a sensing system based on a gold-coated optical fiber is proposed and demonstrated for the monitoring of rapidly changing temperatures at the catalyst's surface. The system is capable of decoding thermal effects in photo-induced catalysis with high temperature and temporal resolutions, without perturbing the catalytic operation. Additionally, stable and reproducible correlations between light-to-heat conversion and catalytic activities over time were measured for different catalysis processes.
LIGHT-SCIENCE & APPLICATIONS
(2022)
Article
Chemistry, Analytical
Hongyuan Li, Hongli Zhao, Zhenxing Wang, Fangfang Zhou, Minbo Lan
Summary: A high-performance microelectrode was developed through a facile method, with PtCu-rGO modification for high-sensitivity detection of H2O2. PtCu bimetallic cluster nanoparticles showed great potential in electrocatalytic of H2O2.
MICROCHEMICAL JOURNAL
(2022)
Article
Chemistry, Physical
Khaja Mohaideen Kamal, Rekha Narayan, Narendraraj Chandran, Stefan Popovic, Mohammed Azeezulla Nazrulla, Janez Kovac, Nika Vrtovec, Marjan Bele, Nejc Hodnik, Marjeta Macek Krzmanc, Blaz Likozar
Summary: In this study, the synthesis and photo catalytic performance of a heterostructure catalyst, ANGT2, consisting of plasmonic gold nanoparticles deposited on TiO2-decorated N-doped graphene, were illustrated. The ANGT2 catalyst demonstrated remarkably enhanced CO2 reduction activity with high selectivity for methane production, achieving the highest reported PCO2R rate under comparable conditions. This superior performance can be attributed to the improved light absorbance, enhanced CO2 uptake, improved charge transfer kinetics, and efficient suppression of photogenerated recombination rate facilitated by the seamless interfacial contact between the components.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Correction
Electrochemistry
Armin Hrnjic, Ana Rebeka Kamsek, Andraz Pavlisic, Martin Sala, Marjan Bele, Leonard Moriau, Matija Gatalo, Francisco Ruiz-Zepeda, Primoz Jovanovic, Nejc Hodnik
ELECTROCHIMICA ACTA
(2022)
Article
Chemistry, Multidisciplinary
Philipp A. Heizmann, Hien Nguyen, Miriam von Holst, Andreas Fischbach, Mitja Kostelec, Francisco Javier Gonzalez Lopez, Marjan Bele, Luka Pavko, Tina Dukic, Martin Sala, Francisco Ruiz-Zepeda, Carolin Klose, Matija Gatalo, Nejc Hodnik, Severin Vierrath, Matthias Breitwieser
Summary: The design of stable and finely dispersed platinum or platinum alloy nanoparticles on the carbon support is crucial for controlling the performance of PEM fuel cells. In this study, a PtCo/C catalyst with intermetallic structures is synthesized and shows significantly narrowed particle size distribution compared to commercial benchmark catalysts. The improved dispersion of PtCo particles leads to an increase in electrochemically active surface area and a more efficient usage of precious metal, resulting in enhanced performance of PEM fuel cells.
Article
Chemistry, Physical
Luka Suhadolnik, Marjan Bele, Miha Cekada, Primoz Jovanovic, Nik Maselj, Anja Loncar, Goran Drazic, Martin Sala, Nejc Hodnik, Janez Kovac, Tiziano Montini, Michele Melchionna, Paolo Fornasiero
Summary: A versatile approach for producing cluster- and single atom-based thin-film electrode composites is described in this article. The TiOxNy-Ir catalyst developed in this study was prepared from sputtered Ti-Ir alloy with 0.8 +/- 0.2 at % Ir in alpha-Ti solid solution. The prepared catalyst exhibited high oxygen evolution reaction activity and has potential applications in electrocatalysis. The article provides a detailed description of the new method and a high-performance thin film catalyst, along with suggestions for future development in this field.
CHEMISTRY OF MATERIALS
(2023)
Article
Electrochemistry
Anja Loncar, Primoz Jovanovic, Nejc Hodnik, Miran Gaberscek
Summary: Recently, a method for determining the actual electrochemically active surface area (ECSA) based on impedance response and adsorption capacity has been proposed. In this paper, the method is applied to characterize Ir-based nanostructured electrocatalysts. Experimental results show deviations from the predicted scaling, which are further analyzed by considering charge transfer resistance, adsorption resistance, and double layer capacitance. Impedance simulations using a full physical model are used to confirm the hypotheses and propose possible reasons for the anomalies.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Maximilian Grandi, Matija Gatalo, Ana Rebeka Kamsek, Gregor Kapun, Kurt Mayer, Francisco Ruiz-Zepeda, Martin Sala, Bernhard Marius, Marjan Bele, Nejc Hodnik, Merit Bodner, Miran Gaberscek, Viktor Hacker
Summary: Platinum-copper catalysts have shown high activity for the oxygen reduction reaction (ORR), but transferring this activity to membrane electrode assemblies (MEAs) has been challenging due to stability issues. The catalysts experience fast performance decay when exposed to repeated voltage load steps with H-2/air supplied. This decay is accelerated by high humidity and low voltage polarization. The use of electrochemical impedance spectroscopy and distribution of relaxation time analysis (EIS-DRT) has helped identify the affected electrochemical processes and suggested improvements for the PtCu/KB catalyst system.
Article
Energy & Fuels
Nik Maselj, Vasko Jovanovski, Francisco Ruiz-Zepeda, Matjaz Finsgar, Tamara Klemencic, Jan Trputec, Ana Rebeka Kamsek, Marjan Bele, Nejc Hodnik, Primoz Jovanovic
Summary: In this study, a comparative analysis of two catalysts for electrocatalytic hydrogenation of furfural under acidic conditions was conducted. The catalysts analyzed were a copper polycrystalline disc and copper nanoparticles dispersed on carbon support. A task-specific methodology based on electrochemistry-mass spectrometry coupling was employed to gain insight into the trends of the hydrogenation reaction. The results showed that the nanoparticulate catalyst exhibited higher activity towards hydrogen evolution and 2-MF production, while the polycrystalline catalyst showed higher selectivity towards furfuryl alcohol. The observed differences in activity were attributed to alterations in surface domains, as supported by surface-sensitive lead underpotential deposition characterization.
Article
Nanoscience & Nanotechnology
Marjan Bele, Gorazd Koderman Podborsek, Anja Loncar, Primoz Jovanovic, Armin Hrnjic, Ziva Marinko, Janez Kovac, Angelja Kjara Surca, Ana Rebeka Kamscek, Goran Drazic, Nejc Hodnik, Luka Suhadolnik
Summary: Introducing the Nano Lab, a novel experimental platform aimed at accelerating the discovery and understanding of promising electrocatalysts. It enables state-of-the-art physicochemical characterization and atomic-scale tracking of individual synthesis steps as well as subsequent electrochemical treatments targeting nanostructured composites. The platform's compatibility with ex situ characterization and other analytical methods allows for a comprehensive understanding of structural changes and their effects.
ACS APPLIED NANO MATERIALS
(2023)
Article
Electrochemistry
Sigrid Wolf, Michaela Roschger, Bostjan Genorio, Nejc Hodnik, Matija Gatalo, Francisco Ruiz-Zepeda, Viktor Hacker
Summary: In this study, researchers synthesized a PdNiBi nanocatalyst on reduced graphene oxide (rGO) using a facile method, which showed higher activity and stability in alkaline direct ethanol fuel cells (ADEFCs). The characterization and electrochemical tests indicated that PdNiBi/rGO had more active sites and exhibited better catalytic performance compared to commercial Pd/C.
JOURNAL OF ELECTROCHEMICAL SCIENCE AND ENGINEERING
(2023)
Article
Nanoscience & Nanotechnology
Hsin-Chia Ho, Milutin Smiljanic, Zoran Jovanovic, Miha Cekada, Janez Kovac, Gertjan Koster, Jiri Hlinka, Nejc Hodnik, Matjaz Spreitzer
Summary: This study developed a robust photocathode using low-cost and high-performing materials, such as p-Si, for efficient and durable production of clean fuel hydrogen. The utilization of pulsed laser deposition (PLD) technique and a buffer layer of reduced graphene oxide (rGO) allowed for the preparation of a high-quality SrTiO3 (STO) layer that passivates the p-Si substrate. The study demonstrated that the epitaxial STO layer on rGO-buffered Si provided the highest onset potential and improved charge separation and transfer compared to counterparts with thicker or nonepitaxial STO layers. The importance of having a well-defined passivation layer and the stability of the epitaxial STO layer in corrosion resistance was also highlighted.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Luka Pavko, Matija Gatalo, Tina Dukic, Francisco Ruiz-Zepeda, Angelja Kjara Surca, Martin Salad, Nik Maselj, Primoz Jovanovic, Marjan Bele, Matjaz Finsgar, Bostjan Genorio, Nejc Hodnik, Miran Gaberscek
Summary: This study evaluates the durability of carbon support materials for Pt alloy nanoparticles and finds that the total amount of oxygen functionalities, the type of oxygen functionalities, and sp2 carbon content play a crucial role in carbon support durability. The findings are confirmed with direct online measurements of carbon corrosion via an advanced in-situ technique.
Article
Electrochemistry
Ozbej Vodeb, Anja Loncar, Marjan Bele, Armin Hrnjic, Primoz Jovanovic, Miran Gaberscek, Nejc Hodnik
Summary: Water splitting in acidic media is an effective method for producing hydrogen fuel, but the oxygen evolution reaction (OER) remains a bottleneck. This study investigates the OER mechanism of three different Ir-based catalysts and the activation process. The results show that all catalysts share the same OER mechanism but require different amounts of activation cycles. This study provides insights into the intrinsic properties of different Ir nanocatalysts and presents a general approach for studying the reaction mechanisms and intrinsic properties of electrocatalysts.
ELECTROCHIMICA ACTA
(2023)
Review
Chemistry, Physical
Chaewon Lim, Alasdair R. Fairhurst, Benjamin J. Ransom, Dominik Haering, Vojislav R. Stamenkovic
Summary: This article provides a comprehensive overview of the application of platinum alloying in improving the activity and stability of electrocatalysts for the oxygen reduction reaction. It focuses on the origin of the effects of transition metals in tuning catalyst functionality, the potential for synergistic application, and their impact on reaction mechanisms and kinetics.
Article
Nanoscience & Nanotechnology
A. R. Kamsek, A. Meden, I. Arcon, P. Jovanovic, M. Sala, F. Ruiz-Zepeda, G. Drazic, M. Gaberscek, M. Bele, N. Hodnik
Summary: In order to reduce the cost of electrocatalysts for oxygen reduction reactions in proton exchange membrane fuel cells, supported metal alloy nanoparticles are commonly used. This study focused on investigating the presence of periodic anti-phase boundaries in carbon-supported PtCu3 nanoparticles. Various characterization tools were used to observe the formation and disappearance of these boundaries. The electrocatalytic activity for the oxygen reduction reaction was determined and correlated with the degree of alloy ordering rather than the presence of anti-phase boundaries.
MATERIALS TODAY NANO
(2023)
Article
Chemistry, Multidisciplinary
L. Moriau, K. Stojanovski, P. Jovanovic, D. Escalera-Lopez, S. Cherevko, N. Hodnik
Summary: The utilization of iridium is expected to increase due to the rising implementation of water electrolyzer devices in the energy transition. However, its limited natural resources make recycling important. The most corrosion resistant platinum group metal, iridium, makes its recovery from waste difficult and energy-demanding. This study examines the impact of organics and chloride ions on the electrochemical dissolution of iridium for green recycling purposes.
