bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of the Magnetostriction Induced on the Crystalline Structure of Nanoparticulate TiO2 Films Supported on Stainless Steel Mesh Electrodes and Their Relationship with the Photocatalytic Decoloration of Aqueous Orange G Solutions
Authors: Valdez Nava Jesus Israel , Bustos Erika , Martinez Rodriguez Laura Lupita , Espejel-Ayala Fabricio , Sepúlveda-Guzmán Selene , Manriquez Juan 
Published: February 2024

The study of ferromagnetism (FM) in non-cubic semiconductor oxides such as defective TiO2 is attractive due to their applications in photocatalysis [1]. FM can be activated in TiO2 nanomaterials by promoting oxygen vacancies (VO) located in paramagnetic defected sites Ti3+VOTi4+. In this context, the VO can induce in Ti3+-doped TiO2 structures remarkable magnetic anisotropy energy (MAE) of 6.51x106 erg/cm3, thus indicating the magnetic saturation should be achieved at magnetic fields (MFs) of ~425 gauss [2,3]. Therefore, magnetostriction can be observed in ferromagnetic TiO2 films as a phenomenon in which their dimensions and shapes are changed when they are magnetized. In this work, stainless steel mesh electrodes (ss) were modified by nanoparticulate TiO2 films (ssTiO2) enriched by Ti3+VOTi4+ sites, to gain an understanding of the effects of magnetostriction on the photocatalytic properties of ferromagnetic TiO2 electrodes. In this way, MFs having intensities (H) of 125, 250, 500, 1000, and 2000 gauss were applied to the ssTiO2 electrodes for 80 min under UV light illumination for increasing the number of Ti3+VOTi4+ sites. Our results revealed that the magnetic lines promoted compression of the TiO2 structure when achieving pressures p>4.67 GPa for H>425 gauss in p=1/2(MAE/4p gauss2)H
2. Consequently, the degree of disorder (0<b<1) of the electron traps at the intra-bandgap state's distribution along the thickness-axis(i.e. the x-axis) of TiO2 films decreased significantly because the fraction of trapped electrons f
trap(x) at the quasi-Fermi level EF(x) was maximized according to f
trap(x)=m[em

(E
F
(x)-E
F
(0))-1], where m=kT/b (k and T are the Boltzmann constant and the absolute temperature) [4,5]. Later, it was observed a significant increase of trapped holes able to carry out the direct photocatalytic oxidation of aqueous orange G (without electron scavenger’s assistance, e.g. gaseous O2). On the other hand, the photogeneration of oxidant •OH radicals decreased dramatically while H increased [6].
[1] Y. Bian et al., RCS Adv.,
11(2021)6284.; [2] D. Kim et al., J. Phys.: Condens. Matter,21(2009)195405.; [3] B. Shao et al., J. Appl. Phys.,115(2014)17A915. [4] N. Kopidakis et al., J. Phys. Chem. B, 107(2003)11307. [5] J. van de Lagemaat et al., J. Phys. Chem. B,104(2000)4292. [6] K.-I Ishibashi et al., J.Photochem.Photobiol.A,134(2000)139-142.

Acknowledgements

The authors thank the National Council for Science and Technology (CONACyT) Mexico for the funding support (grants CB No. 258789 and FOINS No. 3838). JIVN thanks CONACyT for his doctoral fellowship support (grant No. 893260).
Ag Nps@PEDOT Nanocomposite Electrosynthesis at a Polarised Liquid|Liquid Interface
Authors: Cheuquepan William , Quintero Jaime Andrés Felipe , Holzinger Angelika , Scanlon Micheal D. 
Published: February 2024

One of Material Science's main challenges is constantly searching for new versatile materials. In this sense, nanocomposites have emerged as an alternative to new substrates due to their unique properties. These hybrid systems are made up of organic polymers with inorganic components. This ideal "tandem" is made up of organic polymers (for example, poly(3,4-ethylenedioxythiophene) (PEDOT), polypyrrole (PPy) and polyaniline (PANI)) with conductive characteristics because of their highly p-conjugated polymeric chains, unique properties, reversible doping/de-doping processes, and controllable chemical/electrochemical properties. Inorganic compounds, such as metallic nanoparticles (NPs), in the organic matrix provide a high surface area and conductivity, acting as protuberances and highly conductive fillers to form a class of material with multidisciplinary applications [1].
There are several methods to generate organic polymers; the electrochemical process is one of the most used due to its versatility and simplicity. This method implies the electrodeposition of the organic polymer on an electrode surface, eliminating the possibility of obtaining a polymeric material separated from the electrode surface and limiting the areas of applicability (polymer firmly attached to the electrode surface). In this sense, the use of a polarised immiscible liquid|liquid (L|L) interfaces is demonstrated as a novel approach for the electrosynthesis of surfactant-free organic thin films, allowing complete control over the thin film morphology [2].
In this work, we present the electrosynthesis of silver nanoparticles@PEDOT nanocomposites based on EDOT polymerization (PEDOT) and the formation of silver nanoparticles by electrochemical polymerisation at a polarised L|L interface. In thermodynamic terms, the oxidant potential of silver ions is insufficient to oxidise 3,4-ethylenedioxythiophene and generate PEDOT. However, under specific conditions (detailed in this presentation), silver ions are reduced while EDOT monomers are oxidised to PEDOT. A deep knowledge of biphasic electropolymerisation coupled with silver nanoparticle formation will help advance the search for new materials for a broad spectrum of applications (antibacterial, electrocatalysis, SERS substrates, biocompatibility substrates, etc.).
Enhancing Material Analysis with Statistical and Computer Vision Techniques: A Comprehensive Approach for Evaluating Electrode Quality
Authors: Vinayakumar Vineetha , Jain Adarsh , Segets Doris 
Published: February 2024

The optimization of electrodes for electrocatalysis is critical to the efficient operation of energy conversion applications, i.e., performance and efficiency can be improved by optimizing their fabrication process [1]. In the surface microstructure of anodes has been recognized as a fundamental aspect influencing their functionality [2]. Consequently, it is vital to precisely characterize the microstructure of electrodes. Atomic force microscopy (AFM) has demonstrated to be a potent technique for scrutinizing the nanoscale microstructure of anodes. Nevertheless, AFM has limitations in investigating vast areas, thereby posing a challenge when evaluating the surface microstructure of large-scale electrodes.
In this study, we developed a multi-stage data quantification method to overcome the limitations of AFM to measure large electrode areas. The efficacy of the developed approach that combines statistical analysis and computer vision techniques was validated by scrutinizing anodes made under various spray coating process conditions. The results demonstrated that the proposed method facilitated the in-depth evaluation of the degree of homogeneity, surface smoothness, and the presence of cracks or defects, thereby enabling a comprehensive assessment of electrode quality. It was possible to establish structure-performance relationships and delineate the interdependence between surface morphology and anode performance, activity, and cycling stability by combining surface analysis measurements with electrochemical analysis.
In conclusion, this link between surface and electrochemical analysis will provide critical insights into anode performance and, in turn, drive the development of advanced materials for energy conversion technologies. Therefore, we believe our method has a high potential to expand the material scientist's toolkit and extend its application to analyze the micro/nanostructure of diverse materials in a wide range of applications, providing novel insights for their optimization.

References

Siegmund, D., et al., Crossing the valley of death: from fundamental to applied research in electrolysis. Jacs Au, 2021. 1(5): p. 527-535.

Chatenet, Marian, et al. "Water electrolysis: from textbook knowledge to the latest scientific strategies and industrial developments." Chemical Society Reviews (2022).
Engineering Gas Diffusion Electrode Microstructures for the Electrochemical Reduction of CO2
Authors: Amireh Senan F. , Jacquemond Remy Richard , Forner-Cuenca Antoni 
Published: February 2024

The electrochemical reduction of CO2 has the potential to enable a circular economy where the captured CO2 can be utilized to produce valuable chemicals. However, existing CO2 reduction electrolyzers suffer from limited performance (i.e. low current densities) and short operation times (1-200 hours)1. The gas diffusion electrode (GDE) is a key component which determines system durability and enables higher current density operation. Yet, commercially available GDEs are carbon fiber-based materials, which were developed to fulfill the requirements of polymer electrolyte fuel cells and were repurposed for emerging CO2 electrolyzers. While functional, the commercial GDEs microstructure and surface properties do not meet the requirements of CO2 electrolysis flow cells which leads to their failure within short operation hours. These GDEs fail due to flooding through different mechanisms such as electrowetting2, capillary imbibition3, salt precipitation3, and uneven pressure distribution4. Therefore, there is a need to develop novel GDEs with engineered microstructures and wettability for the unique challenges of CO2 electrolyzers.
In this research, we aim to understand the influence of the GDE microstructure on the durability and performance of CO2 electrolyzers. Instead of leveraging commercially available carbon-fiber based substrates, we conceptualize and deploy a scalable technique to manufacture novel GDEs with tunable microstructure. We hypothesize that tackling the multiphase transport challenges in CO2 electrolyzers requires electrode formats containing a plurality of pore sizes and highly controlled microstructures. Thus, we aim to develop a synthetic methodology affording a high degree of microstructural versatility and low manufacturing costs. We investigate the effect of synthetic parameters on the resulting microstructural (e.g. porosity, pore size distribution) and wetting properties. Furthermore, we aim to correlate the synthetic parameters with the resulting GDE properties (e.g. microstructure, porosity) and the corresponding transport properties (e.g. permeability, capillarity, diffusivity). These properties will be further correlated to the flow cell durability and performance. We hypothesize that tuning the pore size distribution and surface chemistry of the GDEs can enhance mass transport rates and resistance to flooding, which could enable longer operating times and higher current density.

References

D. Wakerley et al., Nat Energy, 7, 130–143 (2022).

K. Yang, R. Kas, W. A. Smith, and T. Burdyny, ACS Energy Lett, 6, 33–40 (2021).

M. E. Leonard, L. E. Clarke, A. Forner‐Cuenca, S. M. Brown, and F. R. Brushett, ChemSusChem, 13, 400–411 (2020).

L. M. Baumgartner, C. I. Koopman, A. Forner-Cuenca, and D. A. Vermaas, ACS Sustain Chem Eng, 10, 4683–4693 (2022).
What Controls Activity Trends of Electrocatalytic Water Splitting? - Activation Energy Vs. Frequency Factor
Authors: Zeradjanin Aleksandar R. 
Published: February 2024

Electrocatalytic water splitting is a topic of investigation of numerous research groups for decades. Oxygen evolution reaction (OER), as a more complex and more demanding reaction, is more frequently studied, despite of the fact that the simpler hydrogen evolution reaction (HER), is generally not well understood. Nowadays, recurrent approach to electrocatalysis is conquest for more active and more stable electrode materials, very often lacking significant input to better understanding of reaction mechanisms or understanding of what are the drivers of electrocatalytic activity [1].
Importantly, if one asks the key question from the conceptual point of view, and that is: what are the origins of electrocatalytic activity? - the answer will be, in the predominant majority of cases, like 70 years ago. Namely, paradigm of electrocatalysis is Sabatier principle, that suggests optimal (“not too strong, not too weak”) binding of intermediates as main precondition of high reaction rate [2]. Conventional wisdom suggests that confirmation of this should be relatively simple. Namely, Brönsted-Evans-Polanyi (BEP) relations suggest linear relationship between adsorption energy of key intermediates and activation energy. In other words, if we have reliable values of adsorption energies relevant for the electrochemical environment [3], they should form linear dependence with experimentally obtained activation energies.
However, high-temperature hydrodynamic experiments on HER indicate that reducing of activation energy by tuning of adsorption energy of intermediates is not necessarily beneficial for enhancement of HER rate. Namely, HER rate is strongly influenced by preexponential frequency factor. Therefore, we propose discussion that will analyse several key aspects of HER electrocatalysis: 1) interplay of activation energy and preexponential factor as a driver of electrocatalytic activity 2) are BEP relations relevant for electrocatalysis 3) can we assess adsorption energies experimentally 4) what are relevant descriptors that shed light on HER activation process, 5) what else is important beyond Sabatier principle for rate of HER [1-7].

Figure 1. Graphical illustration of four interfacial descriptors relevant for HER. Adapted from Ref. [4] with permission from the PCCP Owner Societies, under the terms and conditions of the Creative Commons Attribution 3.0 Unported License.

References

[1] A.R. Zeradjanin et al, ChemElectroChem
2022,
9, e202101278
[2] A.R. Zeradjanin et al, Electrochimica Acta
2021,
388, 138583
[3] A.R. Zeradjanin et al, Journal of Solid State Electrochemistry
2021,
25, 33
[4] A.R. Zeradjanin et al, PCCP
2020,
22, 8768
[5] A.R. Zeradjanin et al, PCCP
2017,
19, 17019
[6] A.R. Zeradjanin et al, Electroanalysis
2016,
28, 2256
[7] A.R. Zeradjanin et al, ACS Catalysis
2022, 12, 11597

Figure 1
Insight into the Formation and Catalytic Mechanism of “CO Pool” during Electrocatalytic Conversion of CO2
Authors: He Anbang , Du Jun 
Published: February 2024

The OC-CO coupling reaction, requiring pairs of *CO or *CHO intermediates absorbed on adjacent Cu sites, is the key elementary reaction during the electrocatalytic conversion of CO2 towards C2 products, where the harsh demand of adjacent *CO cause the transmission and preservation of CO species become the critical step of CO coupling reaction. Among the reported M-Cu (M=Ag, Au, Zn, etc....) tandem catalysts and Cu+-Cu sites, CO goes through the route of “generation-desorption-transmission-deeply reduction” over the catalytic surface. Despite the in-depth studies of the various site’s composition, morphological structures, and catalytic sites arrangement on Cu-based catalysts, the migratory manner on the electrode surface and the concentration and reactivity of CO in the double layer is still obscure, which are essential steps for CO spillover on the surface of Cu-based catalysts and further coupling reactions, as well as the underlying causes of the poor selectivity of CO/C2 products. At the same time, in situtechniques with temporal resolution are still lacking for probing the overflow and inter-diffusion of CO in the double layer.
In this study, based on the rotating disk electrode, we developed an effective means for in situ monitoring of the transport and electrochemical properties of CO in the diffusion layer. Based on theoretical analysis of the electrochemical interface CO species transfer path and time-resolved RRDE techniques, we proved that most of the CO intermediates are favorable to transferred and then reserved in the diffusion layer, leading to an enhanced concentration of CO over equilibrium concentration, and finally benefitted the transmission and reactivity of CO species. By analyzing the reaction chain, combined with in situ ATR-SEIRAS monitor and theoretic calculation, the chemical potential was proved to be enhanced by introducing the “CO pool”, which could be resonated in the reaction chain, raised an increased entropy production and finally led to a resonance-enhanced concentration of by-intermediates, finally strengthening the activity of whole chain-system.

Figure 1
Electrochemical Analysis on Transition Metal Nitride Catalysts for Nitrogen Reduction Reaction
Authors: Flosadóttir Helga Dögg , Hanifpour Ása , Skulason Egill 
Published: February 2024

A versatile and sustainable process for ammonia production is needed to ensure a sustainable future for the growing global population, both with regards to fertilizer production as well as energy carrier. Theoretical simulations of transition metal nitride catalysts have demonstrated the possibilityof a nitrogen reduction reaction catalysis cycle on four transition metal nitrides, CrN, VN, ZrN and NbN.[1,2] Reproducible and reliable research and development approaches in the direction of electrochemical reduction of nitrogen towards ammonia are therefore of importance. An operando ammonia quantification methodology for electrochemical catalysis studies has been developed in-house and recently published [3]. Allowing for automatic, quantitative detection of aqueouos ammonia at the ppb level, within minutes from the sample preparation. We have now analyzed all four theoretically proposed TMNs, as well as rutile Niobium oxynitride (NbON) of several stochiometries as thin films on a conductive electrode substrate in ambient environment and aqueouos electrochemical system [3,4].Electrochemical analysis and ammonia quantification suggest NbON of specific stochiometry and ZrN to be promising catalyst candidates, while lacking stability in the environment of choice in these studies.
Literature:
[1] Y. Abghoui, A.L. Garden, J.G. Howalt, T. Vegge and E. Skúlason, Electroreduction of N2 to ammonia at ambient conditions on mononitrides of Zr, Nb, Cr, and V: A DFT guide for experiments. ACS Catalysis, 2016.6(2): p. 635.
[2] Y. Abghoui, A.L. Garden, V.F. Hlynsson, S. Björgvinsdóttir, H. Ólafsdóttir and E.Skúlason, Enabling electrochemical reduction of nitrogen to ammonia at ambient conditions through rational catalyst design. Physical Chemistry Chemical Physics,2015.17(7): p. 4909.
[3] F. Hanifpour, C.P. Canales, E.G. Fridriksson, A. Sveinbjörnsson, T.K. Tryggvason,E. Lewin, . . . H.D. Flosadóttir, Investigation into the mechanism of electrochemical nitrogen reduction reaction to ammonia using niobium oxynitride thin-film catalysts. Electrochimica Acta, 2022.403: p. 139551.
[4] F. Hanifpour, C.P. Canales, E.G. Friðriksson, A. Sveinbjörnsson, T. Tryggvason, Y.Abghoui, . . . E. Skúlason, Operando Quanitification of ammonia produced from computationally derived transition metal nitride electro catalysts. Journal of Catalysis, 2022. 413: p.956
Two-Dimensional Carbon Nitride as a Support of Single Metal Atom for Carbon Dioxide Reduction Reaction
Authors: Posada Perez Sergio , Vidal López Anna , Solà Miquel , Poater Albert 
Published: February 2024

Electrochemical conversion of CO2 into added-value chemicals is an important approach to recycle CO2. Heterogeneous catalysis is widely used in industrial applications because of the possibility of facile separation, which reduces the operating costs, although heterogeneous catalysts often have limited selectivity. In contrast, homogeneous catalysts are very selective although they have limited industrial applications due to their cost, the use of precious metals, and the difficulty in separating and recovering the catalysts. Currently, the research community is trying to combine the properties of homogeneous and heterogeneous catalysts. From the heterogeneous catalyst perspective, research has been focused on creating smaller and dispersed catalyst particles. Single-atom catalysts (SACs), which comprise atoms of metal species dispersed on a solid support, are expected to bridge the homogeneous and heterogeneous catalyst properties.
The work described herein explores, by means of density functional simulations, the electrocatalytic CO2 reduction reaction (CO2RR) using several single transition metal atoms anchored in 2D graphitic carbon nitride (g-C3N4),1 focusing on the group XI transition metals since they include Cu, the only transition metal capable of reducing CO2 to hydrocarbons and alcohols with acceptable faradaic efficiencies. Moreover, the Cu1/g-C3N4 system has been experimentally evaluated as CO2RR electrocatalysts. 2D g-C3N4 has been demonstrated to be a competitive candidate for electrocatalytic CO2 reduction since it can act as an active support for single metal-atom catalysts, mainly Cu, Pd, and Pt, and the deposition of Au single atom was experimentally characterized.
The computational hydrogen electrode model has been used to explore the suitability of several transition metals atoms anchored to C3N4, showing that single atoms enhance the catalytic activity of the system as the first proton–electron transfer is thermodynamically favored in comparison to bare carbon nitride support. Our theoretical interpretations are consistent with the experimental results using Cu1/g-C3N4,2 revealing that the competitive H2 generation is favored due to the strong CO binding energies. This fact reinforced the capability of our computational models to predict the behavior of several single metal atom electrocatalysts to reduce CO2, for instance, predicting that Au can promote the methane formation after eight electron-proton transfer processes. Our computational study paves the road to finding suitable metals that catalyze the first proton–electron transfer in the carbon dioxide reduction reaction.

Posada-Pérez, A. Vidal-López, M. Solà, and A. Poater, 2023, Phys. Chem. Chem. Phys, 25, 8574.

Cometto, A. Ugolotti, E. Grazietti, A. Moretto, G. Bottaro, L. Armelao, C. Di Valentin, L. Calvillo and G. A. Granozzi, npj 2D Mater.
Appl., 2021, 5, 63.

Figure 1