Article
Chemistry, Analytical
Md. Fahamidul Islam, Riad H. Rakib, Khalid A. Alamry, Mohammed M. Rahman, Mohammad A. Hasnat
Summary: In this article, an immobilized IrOx catalyst on ITO surface is proposed for efficient electrocatalytic oxidation of catechol. The catalysis and kinetics were investigated using Cyclic Voltammetric technique, and it was found that the Ir(III) species on the ITO surface can catalyze the catechol oxidation reaction through a redox reaction.
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Lianhai Zu, Xingyue Qian, Shenlong Zhao, Qinghua Liang, Yu Emily Chen, Min Liu, Bing-Jian Su, Kuang-Hsu Wu, Longbing Qu, Linlin Duan, Hualin Zhan, Jun-Ye Zhang, Can Li, Wei Li, Jenh Yih Juang, Junwu Zhu, Dan Li, Aibing Yu, Dongyuan Zhao
Summary: In this work, ultrathin Ir-IrOx/C nanosheets with ordered interlayer space were synthesized through a nanoconfined self-assembly strategy, exhibiting enhanced catalytic activity for acidic oxygen evolution reactions. The nanosheets showed one of the lowest overpotential during OER in an acid medium, benefiting from their mixed-valence states, rich electrophilic oxygen species, and favorable mesostructured architectures. This study opens a new avenue for designing high-performance 2D ordered mesoporous electrocatalysts for water oxidation and beyond through a nanoconfined self-assembly strategy.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Uddipana Kakati, Evert J. J. Elzinga, Zachary R. R. Mansley, Benjamin Roe, Farbod Alimohammadi, Gregory Schwenk, Jinliang Ning, Yimei Zhu, Hai-Feng Ji, Jianwei Sun, Daniel R. R. Strongin
Summary: In this study, we investigated the structure and activity of electrocatalysts with low loadings of Ir incorporated into 2D layered MnO2 and 3D MnO2 for the oxygen evolution reaction (OER). We prepared Ir-incorporated beta-MnO2 catalysts for the first time via a thermally induced phase transition of delta-MnO2 containing 16-22 wt% Ir. The catalyst consisted of Ir substituted into the crystalline beta-MnO2 lattice, and showed lower OER overpotential than commercial IrO2 in 0.5 M H2SO4.
Article
Chemistry, Multidisciplinary
Juan-Jesus Velasco-Velez, Emilia A. Carbonio, Cheng-Hao Chuang, Cheng-Jhih Hsu, Jyh-Fu Lee, Rosa Arrigo, Michael Haevecker, Ruizhi Wang, Milivoj Plodinec, Feng Ryan Wang, Alba Centeno, Amaia Zurutuza, Lorenz J. Falling, Rik Valentijn Mom, Stephan Hofmann, Robert Schloegl, Axel Knop-Gericke, Travis E. Jones
Summary: Iridium and ruthenium based anodes show low overpotentials and high corrosion resistance, making them ideal for the oxygen evolution reaction under harsh acidic conditions. Through advanced X-ray spectroscopy techniques, electrode nanofabrication, and DFT calculations, researchers revealed that the oxygen evolution reaction is controlled by the formation of empty Ir 5d states on the surface, while oxygen bound to three iridium centers remains dominant in the bulk. Furthermore, the study found that a high coverage of μ(1)-OO (peroxo) species during the OER is excluded, and a higher surface-to-bulk ratio in thinner electrodes enhances material usage.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Shao-Xiong Lennon Luo, Richard Y. Liu, Sungsik Lee, Timothy M. Swager
Summary: This study reports the synthesis of new carbon-nanomaterial-based metal chelates for effective electronic coupling to electrocatalytic transition metals. The functional carbon nanomaterials covalently bind precious and earth-abundant metals to form materials with high metal contents. Experimental and computational studies reveal the importance of the defined ligands on graphene surfaces for structurally precise heterogeneous molecular catalysts. The direct attachment of isoxazoline functional groups on graphene surfaces provides strong electronic coupling with chelated metal species, demonstrating effective heterogeneous catalysis in the oxygen evolution reaction.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Electrochemistry
Naghmehalsadat Mirbagheri, Rui Campos, Elena E. Ferapontova
Summary: This study investigated the effect of different capping ligands and electrode substrates on the electrocatalysis of iridium oxide nanoparticles for water oxidation reaction. The results showed that the hydrophilic properties of the electrode substrate could affect the morphology and catalytic performance of the formed iridium oxide films.
Article
Chemistry, Multidisciplinary
Xiaohe Tan, Mingkai Zhang, Da Chen, Wenbin Li, Wangyan Gou, Yongquan Qu, Yuanyuan Ma
Summary: Recent advances have shown that OER catalysts can bypass limitations through lattice oxygen-mediated mechanism (LOM) instead of adsorbate evolution mechanism (AEM). IrOx, the most promising OER catalyst, has low activity in its AEM pathway. However, a pre-electrochemical etching treatment on IrOx/Y2O3 hybrids can switch the OER pathway from AEM-dominated to LOM-dominated, resulting in high performance and stability in alkali electrolyte.
Article
Chemistry, Physical
E. A. Carbonio, F. Sulzmann, D. Teschner, J. J. Velasco-Velez, M. Havecker, A. Knop Gericke, R. Schlogl, T. Jones
Summary: Water splitting is a promising technology for renewable energy, but the sluggishness of the oxygen evolution reaction (OER) is a major challenge. Iridium-based oxides are attractive materials for the OER, but they also have high dissolution rates. In contrast, rutile-type IrO2 has high dissolution resistance but lower OER activity. This study shows that the same OI- species can be formed on IrIV+delta without the presence of Ir-III species, shedding light on the link between OI- and Ir-III species.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Qianhong Tian, Zixiang Zhou, Rui Wang, Jianlong Zhang, Chao Wang
Summary: Water electrolysis is a promising method for large-scale hydrogen production using renewable energy. In this study, ultrasmall IrOx incorporated nitrogen-doped carbon electrodes were prepared and exhibited high activity and stability for water oxidation reaction (WOR) in acid. The electrode showed low overpotential and high specific activity, indicating excellent performance. A water electrolyzer was also assembled, achieving low cell voltage and high current density.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Danilo Gonzalez, Mariona Sodupe, Luis Rodriguez-Santiago, Xavier Solans-Monfort
Summary: H-2 production through water electrolysis is a promising strategy for storing sunlight energy. Iridium oxide containing materials are the state-of-the-art for the oxygen evolution reaction, with small nanoparticles showing high catalytic activities. This study performed DFT calculations to determine the factors controlling the catalytic activity of IrO2 nanoparticles.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Physical
Yang Hu, Haowen Chen, Qiyang Lu
Summary: This study investigates the phase equilibrium and kinetics of the phase transition in CoOxHy driven by applied electrochemical driving force using operando Raman spectroscopy and operando optical characterization. The researchers found an irreversible phase transition in the first electrochemical test, but the transition became fully reversible in each following cycle. By establishing the relationship between kinetic parameters of the reversible phase transition and applied potential, this work provides a precise approach toward understanding the electrochemically driven phase transition in OER electrocatalysts.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Yingliang Feng, Sifan Zhang, Lihua Zhu, Guoda Li, Ning Zhao, Huan Zhang, Bing Hui Chen
Summary: Hydrogen energy has gained significant attention due to its high energy density and lack of carbon dioxide emissions, making it a valuable green energy source. Water electrolysis for hydrogen production offers great potential due to its cleanliness and lack of pollution. However, developing an efficient, stable, and cost-effective electrocatalyst remains a challenge. In this study, researchers have developed a reduced graphene oxide-supported ruthenium (Ru) nanoparticle electrocatalyst using a simple method. The Ru/rGO catalyst demonstrates excellent electrocatalytic activity and long-term stability for the hydrogen evolution reaction. It outperforms commercial Pt/C and other Ru/rGO catalysts in terms of performance. This work presents a new strategy for synthesizing efficient electrocatalysts.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Multidisciplinary
Xiao Liang, Wensheng Yan, Yinglong Yu, Kexin Zhang, Wei An, Hui Chen, Yongcun Zou, Xiao Zhao, Xiaoxin Zou
Summary: Improving catalytic activity without compromising catalytic stability is a core goal in the search for low-iridium-content oxygen evolution electrocatalysts under acidic conditions. In this study, a family of SrBO3 perovskite oxides with different Ti : Ru : Ir atomic ratios was synthesized, and catalytic activity-stability maps were constructed. These maps classify the multicomponent perovskites into chemical groups with distinct catalytic activity and stability, highlighting a chemical region where high catalytic activity and stability are achieved simultaneously at a relatively low iridium level.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Kai Zhang, Chunlei Liu, Nigel Graham, Gong Zhang, Wenzheng Yu
Summary: A research study presented a facile strategy for the controllable fabrication of the bimetallic active Co2Mo3O8 electrocatalyst for alkaline urea splitting. The synergistic effect of the Co-Mo dual sites was confirmed, and theoretical calculations revealed key features determining high reactivity for urea oxidation.
Article
Chemistry, Physical
Woo Tae Jun, Ji Young Hwang, Hyung-Kyu Lim, Duck Hyun Youn
Summary: A composite catalyst of IrOx nanoparticles dispersed in CeO2 support (IrOx/CeO2) was prepared for oxygen evolution reaction (OER), showing excellent performance and stability. The lower-valance Ir3+ species near the catalyst surface served as active sites for OER.
APPLIED SURFACE SCIENCE
(2024)
Article
Biochemistry & Molecular Biology
Francisco Sanchez-Ferez, Joaquim Ma Rius-Bartra, Jose A. Ayllon, Teresa Calvet, Merce Font-Bardia, Josefina Pons
Summary: Aggregation between molecules is crucial for preventing aggregation-caused quenching. By incorporating ligands with different intra- and intermolecular interaction biases, absorption and emission properties can be compared. Properties of functional groups and coordination modes affect the photophysical properties.
Article
Chemistry, Inorganic & Nuclear
Francisco Sanchez-Ferez, Xavier Solans-Monfort, Teresa Calvet, Merce Font-Bardia, Josefina Pons
Summary: Controlling the formation of desired product in the appropriate crystalline form is a fundamental breakthrough in crystal engineering. In this study, the formation of two concomitant polymorphs was observed, which originated from the Hg(II) cores and intermolecular associations, particularly indicated by Hg···π and π···π interactions. The selective synthesis of these polymorphs was successfully achieved by changing the synthetic conditions, and significant variations in solid-state photoluminescence were found due to differences in stability between the polymorphs.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Daniel Ejarque, Teresa Calvet, MercS Font-Bardia, Josefina Pons
Summary: The study synthesized four Zn(II) CPs involving alpha-acetamidocinnamic acid and 4,4'-bipyridine, and investigated their crystal structures and reversibility through different reactions and structural transformations. The research revealed the variations in properties and photoluminescence effects of these CPs due to structural differences and solvent/temperature influence.
CRYSTAL GROWTH & DESIGN
(2022)
Review
Biochemical Research Methods
Celia Toyos-Rodriguez, David Valero-Calvo, Alfredo de la Escosura-muniz
Summary: The abusive use of antimicrobial compounds and the associated appearance of antimicrobial resistant strains pose a major threat to human health. Improved antimicrobial administration requires faster diagnosis and detection of resistances. Electrochemical methods used in antimicrobial susceptibility testing (AST), particularly for evaluating new drug candidates, have shown significant potential. The role of nanomaterials in these biosensing platforms is relatively minor compared to other applications.
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2023)
Review
Chemistry, Analytical
Ana Rubio-Monterde, Daniel Quesada-Gonzalez, Arben Merkoci
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Annalisa Scroccarello, Ruslan Alvarez-Diduk, Flavio Della Pelle, Cecilia de Carvalho Castro e Silva, Andrea Idili, Claudio Parolo, Dario Compagnone, Arben Merkoci
Summary: The combination of two-dimensional materials and metal nano-particles allows the fabrication of nanocomposites for high-performance smart devices and biosensors. This study proposes a single-step technique to produce reduced graphene oxide conductive films integrating naked noble metal nano-particles. The produced films have been fully characterized and integrated into various sensors to detect different analytes with high accuracy.
Article
Nanoscience & Nanotechnology
Lei Zhao, Giulio Rosati, Andrew Piper, Cecilia de Carvalho Castro e Silva, Liming Hu, Qiuyue Yang, Flavio Della Pelle, Ruslan R. Alvarez-Diduk, Arben Merkoci
Summary: Graphene-based materials have unique properties that make them suitable for electro-chemical biosensing. However, the production of graphene electrodes on a large scale remains challenging. This study presents a simple and fast method for fabricating reduced graphene oxide electrodes using direct writing and stamp-transferring techniques. The biosensors developed using these electrodes demonstrated excellent sensitivity and detection limits for Escherichia coli, making them suitable for real-world applications.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Analytical
David Valero-Calvo, Celia Toyos-Rodriguez, Francisco Javier Garcia-Alonso, Alfredo de la Escosura-Muniz
Summary: For the first time, nanoparticles are suggested as carriers of an immobilized enzymatic substrate in nanoporous alumina membranes to enhance nanochannel blocking and improve enzyme determination efficiency. Polystyrene nanoparticles modified with streptavidin are proposed as carrier agents, providing steric and electrostatic blockage due to their charge at different pH values. The effect of using negatively charged and positively charged redox indicator ions on electrostatic blockage is studied for the first time. The approach shows great potential in point-of-care diagnostics with cheap and fast sensing methodology, allowing detection of clinically relevant levels of matrix-metalloproteinase 9 with good reproducibility and selectivity.
Article
Nanoscience & Nanotechnology
Lourdes Rivas, Arben Merkoci, Liming Hu, Claudio Parolo, Andrea Idili
Summary: The use of nanomaterials as colorimetric labels in point-of-care devices can enhance sensitivity. By optimizing the synthesis of gold and iridium oxide nanoflowers, researchers have achieved improved colorimetric signals and sensitivity, making them potential candidates for the next generation of optical lateral flow assays.
ACS APPLIED NANO MATERIALS
(2023)
Article
Food Science & Technology
Beatriz Perez-Fernandez, Britt Marianna Maestroni, Shuichi Nakaya, Sofia Bussalino, Christina Vlachou, Alfredo de la Escosura-Muniz
Summary: Aflatoxins (AFs) can be produced by fungi in nuts, and their levels in food are strictly regulated due to their adverse effects on humans. Electrochemical immunosensing is a sensitive and cost-effective alternative to standard AFs analysis, and has been used for the detection of AFB1. However, the determination of total AFs is not widely reported with electrochemical immunosensors.
Article
Chemistry, Multidisciplinary
Gabriel Maroli, Vernalyn Abarintos, Andrew Piper, Arben Merkoci
Summary: This article reports a method of fabricating nanoband electrodes using low-cost materials and equipment, which have advantages of low cost, fast production, and high flexibility. The research shows that these nanoband electrodes have single molecule sensitivity for the detection of DNA sequences specific to SARS-CoV-2.
Article
Chemistry, Analytical
Ana M. Villa-Manso, Tamara Guerrero-Esteban, Felix Pariente, Celia Toyos-Rodriguez, Alfredo de la Escosura-Muniz, Monica Revenga-Parra, Cristina Gutierrez-Sanchez, Encarnacion Lorenzeo
Summary: A novel immunosensor based on electrochemiluminescence resonance energy transfer (ECL-RET) has been developed for the sensitive determination of N protein of the SARS-CoV-2 coronavirus. The immunosensor utilizes bifunctional core@shell nanoparticles as ECL acceptor and [Ru(bpy)(3)](2+) as ECL donor. It demonstrates a wide linear response to the concentration of N protein with a detection limit of 1.27 pg/mL, high stability, and specificity. The immunosensor has been successfully applied for quantification of N protein in saliva samples and showed consistent results with a commercial colorimetric ELISA kit.
Article
Chemistry, Multidisciplinary
Flavio Della Pelle, Qurat Ul Ain Bukhari, Ruslan Alvarez Diduk, Annalisa Scroccarello, Dario Compagnone, Arben Merkoci
Summary: We introduce a CO2 laser plotter-based technology for the production of heterostructures (HTs) comprising reduced graphene oxide (rGO) and 2D transition metal dichalcogenides (TMDs). The laser treatment converts GO into highly exfoliated and conductive rGO decorated with small TMD/TM-oxide nanoflakes. The freestanding LIHT films obtained exhibit excellent performance as self-contained sensors with nanomolar limits of detection and high fouling resistance.
Article
Chemistry, Multidisciplinary
Yang Qiuyue, Emily P. Nguyen, David Panacek, Veronika Sedajova, Vitezslav Hruby, Giulio Rosati, de Carvalho Castro Silva Cecilia, Aristides Bakandritsos, Michal Otyepka, Arben Merkoci
Summary: Heavy metal pollutants are highly toxic and pose great concern in environmental monitoring. Electrochemical detection, hindered by mutual interferences of heavy metal ions, is a main technique with limited sensitivity to Cd2+ ions. This study introduces a metal-free and sustainable nanomaterial, cysteamine covalently functionalized graphene (GSH), which significantly enhances the sensitivity of screen-printed carbon electrode (SPCE) to Cd2+ ions while maintaining sensitivity to other heavy metals. The enhancement is attributed to the grafted thiols on the GSH sheets with strong affinity to Cd2+ ions, based on Pearson's principle. The GSH-modified SPCE also exhibits high reusability and outperforms existing SPCEs modified by non-covalently functionalized graphene derivatives. The GSH-SPCE is successfully validated in tap water.
Article
Chemistry, Multidisciplinary
Massimo Urban, Giulio Rosati, Gabriel Maroli, Flavio Della Pelle, Andrea Bonini, Laszlo Sajti, Mariangela Fedel, Arben Merkoci
Summary: This study presents a new sintering method called click sintering, which uses a catalytic reaction to enhance and tune the nanostructuration of gold nanoparticle inks. This one-step approach allows for the creation of conductive and electroactive nanoporous thin films without the need for complex post-treatments. The properties of the film can be adjusted by controlling the reaction conditions. The click sintering strategy offers a rapid, easy, and inexpensive technique for fabricating functional nanostructures, with potential applications in flexible electronics, biosensing, energy, and catalysis.
