Article
Chemistry, Physical
Alex Ricardo Silva Olaya, Franziska Kuehling, Christoph Mahr, Birthe Zandersons, Andreas Rosenauer, Joerg Weissmueller, Gunther Wittstock
Summary: Nanoporous gold (NPG) with less than 1% residual Ag content was studied as an electrocatalyst for the oxidation of methanol, formaldehyde, and formate. The surface structure and oxidation reaction of NPG can be controlled by adjusting the Ag content and potential. Ag has a significant impact on the onset potential and peak current density of the catalytic reaction.
Article
Engineering, Electrical & Electronic
Jung-Chuan Chou, Kun-Tse Lee, Po-Hui Yang, Po-Yu Kuo, Yu-Hsun Nien, Chih-Hsien Lai, Ying-Sheng Chang
Summary: We developed a potentiometric nonenzymatic ascorbic acid (AA) sensor using molybdenum trioxide (MoO3) film and copper oxide nanoparticles (CuO NPs) as the main sensing materials. The sensors and sensing materials were fabricated using screen printing technique, radio frequency sputtering system, and green synthesis method. We examined the average sensitivity, linearity, and interference effects of the AA sensor under static measurements, and performed experiments using a microfluidic system to analyze the best sensing characteristic under dynamic measurements. The AA sensor achieved better stability and accuracy with the help of a unity-gain frequency and low power consumption instrumentation amplifier (UGFPCIA).
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Chemistry, Analytical
Gamze Emir, Yusuf Dilgin, Almira Ramanaviciene, Arunas Ramanavicius
Summary: The study presents a non-enzymatic electrocatalytic amperometric glucose biosensor using a graphite rod electrode modified with Ni nanoparticles and polypyrrole. The sensor demonstrated efficient electrocatalytic oxidation activity towards glucose and a wide linear glucose determination range.
MICROCHEMICAL JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Tianheng Sun, Xin Cheng, Dongzhi Zhang
Summary: This study reported a low-cost, highly sensitive nonenzymatic glucose sensor based on CuCo2O4 nanoparticles. The CuCo2O4 nanoparticles were synthesized using oxalic acid and sodium hydroxide, and exhibited superior glucose sensing performance compared to NaOH-assisted CuCo2O4. The sensor showed good selectivity, repeatability, and long-term stability.
IEEE SENSORS JOURNAL
(2022)
Article
Engineering, Biomedical
Qie Fang, Hengjia Wang, Xiaoqian Wei, Yinjun Tang, Xin Luo, Weiqing Xu, Liuyong Hu, Wenling Gu, Chengzhou Zhu
Summary: Developing functional nanomaterials for nonenzymatic glucose electrochemical sensing platforms is important and challenging. Cu aerogels are synthesized as a model system for sensitive nonenzymatic glucose sensing. In situ electrochemical investigations and Raman characterizations reveal the catalytic mechanism of Cu-based nonenzymatic glucose sensing.
ADVANCED HEALTHCARE MATERIALS
(2023)
Article
Electrochemistry
Abiola V. M. Oladej, James Courtney, Neil V. Rees
Summary: This study demonstrates the possibility of depositing metals onto low-metal content particles using impact electrochemistry. Copper deposition on fly-ash cenospheres as well as silver and gold nanoparticles was achieved through electrochemical impacts. The correlation between impact signals and deposition potentials was confirmed. The electrochemical activity of cenospheres was shown to facilitate copper deposition, which was confirmed through SEM/EDX and ICP-MS analysis.
ELECTROCHIMICA ACTA
(2022)
Article
Chemistry, Multidisciplinary
Betty Edem Nugba, A. A. El-Moneim, Nahla O. Mousa, Ahmed Osman
Summary: By using a simple galvanic pulse electrodeposition approach, a unique nonenzymatic glucose amperometric electrode was developed based on 3D structure laser-induced graphene. The electrode exhibited high sensitivity, fast response time, wide linear range, and low detection limit, making it suitable for accurate glucose sensing in saliva.
Article
Physics, Applied
Ryan R. Gusley, Quintin Cumston, Kevin R. Coffey, Alan C. West, Katayun Barmak
Summary: The electrodeposition of Cu onto epitaxial Ru(0001) seed layers resulted in the growth of a bicrystal structure with an improvement in resistivity, despite the compressive misfit strain between the layers. The Cu initially grew as isolated islands before coalescing into a rough, contiguous film with large grain sizes. As the thickness increased, the film transitioned into a planar film with nanometric islands, but at thicknesses exceeding 200 nm, anisotropic growth led to increased surface roughness.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Electrochemistry
Istvan Bakos, Adam Vass, Eric S. Muckley, Ilia N. Ivanov, Zsofia Keresztes
Summary: In this study, the use of copper underpotential deposition (UPD) was demonstrated to measure the electrochemically active surface area of a protein-modified gold electrode. The adsorption behavior of beta-casein was found to be influenced by the surface roughness, microstructure of the gold electrode, and the concentration of the protein solution.
ELECTROCHEMISTRY COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Zhi-Zheng Wu, Xiao-Long Zhang, Zhuang-Zhuang Niu, Fei-Yue Gao, Peng-Peng Yang, Li-Ping Chi, Lei Shi, Wen-Sen Wei, Ren Liu, Zhi Chen, Shaojin Hu, Xiao Zheng, Min-Rui Gao
Summary: The study demonstrates that oxide-derived copper crystals enclosed by Cu(100)/Cu(111) interfaces can efficiently reduce CO2 to multicarbon products with high Faradaic efficiency. Combining experimental and computational studies reveals that these interfaces have a favorable local electronic structure that enhances catalytic activity.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Materials Science, Multidisciplinary
Baleeswaraiah Muchharla, Brianna Barbee, Marlon Darby, Wei Cao, Hani Elsayed-Ali, Kishor Kumar Sadasivuni, Adetayo Adedeji, Kapil Kumar, Abdennaceur Karoui, Preety Panwar, Gymama Slaughter, Bijandra Kumar
Summary: In this study, we prepared a copper nanofibril assembly using thermal oxidation and electrochemical reduction processes. The resulting structure exhibited excellent glucose detection ability with a high sensitivity, low detection limit, wider linear range, and long-term stability. The enhanced glucose sensing ability of the copper nanofibril structure can be attributed to its morphology, origin of the Cu (111) facet, and formation of a stable oxide layer. This structure showed no response to other interfering substances such as chloride ion, dopamine, ascorbic acid, and uric acid, making it a promising candidate for glucose sensing applications.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Xiafang Ji, Peng Chen, Yuanjun Liu, Zhenyuan Ji, Hongbo Zhou, Caiyao Chen, Xiaoping Shen, Xiaoqi Fu, Guoxing Zhu
Summary: In this study, Ir/Ni-NiO/CNT composite catalysts were designed and prepared. The as-prepared catalyst exhibited excellent catalytic performance in alkaline media, surpassing commercial Pt/C catalysts. Experimental and theoretical calculations showed that the presence of Ni-NiO facilitated the Volmer step for HOR by weakening the hydrogen binding energy on Ir sites.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Materials Science, Multidisciplinary
Ezer Castillo, Jackson Zhang, Nikolay Dimitrov
Summary: Nanoporous copper films with fine ligament length scales and high surface area were prepared using an all-electrochemical approach. The parameters that were found to affect the resulting film structure were the composition of the dealloying bath, the atomic composition of the precursor alloy, and the addition of nickel. By controlling these parameters, a wide range of nano-scaled nanoporous copper films with specific surface characteristics were obtained.
Article
Nanoscience & Nanotechnology
Fang-Yu Lin, Pei-Yuan Lee, Tien-Fu Chu, Chang- Peng, Gou-Jen Wang
Summary: The study introduces a Pt/Au alloy electrode for enzyme-free glucose detection in a neutral environment with excellent specificity and sensitivity, showing feasibility for clinical applications.
INTERNATIONAL JOURNAL OF NANOMEDICINE
(2021)
Article
Materials Science, Multidisciplinary
Busra Ozlu, Bong Sup Shim
Summary: This study successfully synthesized highly electrically conductive melanin-like polymers (eMLPs) and demonstrated their potential application in glucose detection. The electrochemical performances of eMLP were significantly improved, and the morphology could be modulated without compromising the properties.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Chemistry, Analytical
Cameron L. Bentley, Minkyung Kang, Patrick R. Unwin
ANALYTICAL CHEMISTRY
(2020)
Review
Chemistry, Physical
Oluwasegun J. Wahab, Minkyung Kang, Patrick R. Unwin
CURRENT OPINION IN ELECTROCHEMISTRY
(2020)
Article
Multidisciplinary Sciences
J. Tyler Mefford, Andrew R. Akbashev, Minkyung Kang, Cameron L. Bentley, William E. Gent, Haitao D. Deng, Daan Hein Alsem, Young-Sang Yu, Norman J. Salmon, David A. Shapiro, Patrick R. Unwin, William C. Chueh
Summary: Transition metal (oxy)hydroxides are promising electrocatalysts for the oxygen evolution reaction, with their properties evolving dynamically and heterogeneously with applied voltage. By studying single-crystalline beta-Co(OH)(2) platelet particles, researchers have found that the particles change structure and composition from inactive to active states as the voltage increases, ultimately linking bulk ion-insertion with surface catalytic activity. This study demonstrates the importance of understanding the nanoscale structure of electrocatalysts in predicting and optimizing their oxygen evolution activity.
Article
Chemistry, Physical
Ruperto G. Mariano, Minkyung Kang, Oluwasegun J. Wahab, Ian J. McPherson, Joshua A. Rabinowitz, Patrick R. Unwin, Matthew W. Kanan
Summary: The study demonstrates that understanding the relationship between surface catalytic activity and bulk defects, such as dislocations, could lead to improvements in catalytic properties, particularly in CO2 electroreduction. Intentionally introducing dislocations into materials appears to be a promising strategy for enhancing catalytic activity.
Review
Chemistry, Multidisciplinary
Si-Xuan Guo, Cameron L. Bentley, Minkyung Kang, Alan M. Bond, Patrick R. Unwin, Jie Zhang
Summary: This article introduces two advanced spatiotemporal voltammetric techniques for electrocatalytic studies, which provide important insights into the electrochemical reduction of CO2. Fourier transformed large-amplitude alternating current voltammetry allows the resolution of rapid electron-transfer processes, while scanning electrochemical cell microscopy provides high-resolution activity maps and potentiodynamic movies of catalyst surfaces.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Multidisciplinary Sciences
Dan-Qing Liu, Minkyung Kang, David Perry, Chang-Hui Chen, Geoff West, Xue Xia, Shayantan Chaudhuri, Zachary P. L. Laker, Neil R. Wilson, Gabriel N. Meloni, Marko M. Melander, Reinhard J. Maurer, Patrick R. Unwin
Summary: The study combines experimental and theoretical methods to investigate the outer-sphere electron transfer mechanism at graphene grown on a copper electrode, revealing slower kinetics for multi-layer graphene compared to monolayer graphene.
NATURE COMMUNICATIONS
(2021)
Article
Electrochemistry
Daniel Martin-Yerga, Minkyung Kang, Patrick R. Unwin
Summary: This study uses scanning electrochemical cell microscopy (SECCM) to investigate the formation of solid-electrolyte interphase (SEI) on graphite surfaces in Li-ion batteries. The presence of step edges on the surface promotes the formation of a more passivating SEI. The study also shows that an unstable SEI can be detected under fast formation conditions, while a slow formation rate leads to the growth of an increasingly passivating SEI.
Article
Chemistry, Multidisciplinary
Cameron L. Bentley, Minkyung Kang, Saheed Bukola, Stephen E. Creager, Patrick R. Unwin
Summary: In this study, local ion-flux imaging was performed on chemical vapor deposition (CVD) graphene vertical bar Nafion membranes using an electrochemical ion (proton) pump cell mode of scanning electrochemical cell microscopy (SECCM). The results show that most of the CVD graphene vertical bar Nafion membrane is impermeable to proton transport, with transmission occurring at localized sites across a small area of the membrane. This suggests that rare atomic defects are responsible for proton conductance.
Article
Chemistry, Analytical
Oluwasegun J. Wahab, Minkyung Kang, Gabriel N. Meloni, Enrico Daviddi, Patrick R. Unwin
Summary: This study investigates nanoscale electrochemistry at indium tin oxide (ITO) electrodes using high-resolution scanning electrochemical cell microscopy (SECCM). The research reveals the spatially heterogeneous charge transfer activity of ITO surfaces and measures a significantly higher charge transfer rate at the nanoscale compared to the macroscale.
ANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Physical
Oluwasegun J. Wahab, Minkyung Kang, Enrico Daviddi, Marc Walker, Patrick R. Unwin
Summary: Understanding how crystallographic orientation affects the electrocatalytic performance of metal catalysts is crucial for improving catalyst efficiency. This study combines scanning electrochemical cell microscopy (SECCM) with electron backscatter diffraction (EBSD) to investigate the correlation between surface crystallographic orientations on polycrystalline copper (Cu) and activity under CO2 electroreduction conditions. The results show that the order of activity is (111) < (100) < (110) among the Cu primary orientations. Furthermore, the study reveals that the ease of electrochemical stripping of the naturally formed passive layer on Cu is grain-dependent, with low-index facets being easier to strip. This research provides a method to rank the most active surfaces for further study.
Article
Chemistry, Multidisciplinary
Cameron L. Bentley, Lachlan F. Gaudin, Minkyung Kang
Summary: Local voltammetric analysis with a scanning electrochemical droplet cell technique, in combination with a new data processing protocol, is used to directly identify previously unseen regions of elevated electrocatalytic activity on the basal plane of molybdenum disulfide. Understanding the nature of these microscopic catalytic active sites is crucial for the rational design of renewable fuel production materials.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Xiangdong Xu, Daniel Martin-Yerga, Nicholas E. Grant, Geoff West, Sophie L. Pain, Minkyung Kang, Marc Walker, John D. Murphy, Patrick R. Unwin
Summary: Understanding the formation of SEI and (de)lithiation phenomena at silicon electrodes is crucial for improving the performance and longevity of Si-based lithium-ion batteries. However, these processes are still elusive, particularly the role of Si surface termination.
Article
Chemistry, Multidisciplinary
Minkyung Kang, Cameron L. Bentley, J. Tyler Mefford, William C. Chueh, Patrick R. Unwin
Summary: This study investigates the variations in electrochemical properties of nanostructured electrocatalysts at different length scales, particularly focusing on the oxygen evolution reaction (OER) activity of beta-Co(OH)(2) platelet particles. The results reveal the significance of heterogeneous activity at the single-particle level, as well as the importance of factors such as particle structure, particle-support interaction, and presence of defects, in governing the electrochemical activities of these materials. The study suggests a roadmap for the rational design and optimization of nanostructured electrocatalysts for alkaline water electrolysis.
Article
Chemistry, Physical
Oluwasegun J. Wahab, Minkyung Kang, Enrico Daviddi, Marc Walker, Patrick R. Unwin
Summary: This study investigates the influence of crystallographic orientation on the electrocatalytic performance of polycrystalline copper (Cu) in CO2 electroreduction. The results demonstrate a correlation between step and kink density of secondary surface facets and electroreduction activity. Additionally, the ease of oxide removal on low-index facets is found to follow the order of (100) > (111) > (110).
Article
Chemistry, Analytical
Baoping Chen, David Perry, James Teahan, Ian J. McPherson, James Edmondson, Minkyung Kang, Dimitrios Valavanis, Bruno G. Frenguelli, Patrick R. Unwin
Summary: An artificial synapse has been developed to mimic ultramicroelectrode (UME) amperometric detection of single cell exocytosis by rapidly pulsing neurotransmitters like dopamine locally and on demand at defined locations on a carbon fiber (CF) UME in each experiment. Analysis of the resulting data reveals spatiotemporal heterogeneous electrode activity at the nanoscale and submillisecond time scale for dopamine electrooxidation, which is related to heterogeneities in the surface chemistry of the CF UME as shown through complementary surface charge mapping and finite element method (FEM) simulations.
ACS MEASUREMENT SCIENCE AU
(2021)
