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54. Green and easy synthesis of P-doped carbon-based hydrogen evolution reaction electrocatalysts

Author

Agence Nationale de la Recherche (France), Université de Lorraine (France), European Commission, Ministerio de Universidades (España), Universidad de Oviedo, Universidad de Alicante, García Dalí, Sergio [0000-0002-0042-0430], Quílez Bermejo, J. [0000-0003-2808-1036], Castro Gutiérrez, Jimena [0000-0002-6319-2498], Baccile, Niki [0000-0003-3142-3228], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], García-Dalí, Sergio, Quílez Bermejo, J., Castro Gutiérrez, Jimena, Baccile, Niki, Izquierdo Pantoja, María Teresa, Celzard, Alain, Fierro, Vanessa, Agence Nationale de la Recherche (France), Université de Lorraine (France), European Commission, Ministerio de Universidades (España), Universidad de Oviedo, Universidad de Alicante, García Dalí, Sergio [0000-0002-0042-0430], Quílez Bermejo, J. [0000-0003-2808-1036], Castro Gutiérrez, Jimena [0000-0002-6319-2498], Baccile, Niki [0000-0003-3142-3228], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], García-Dalí, Sergio, Quílez Bermejo, J., Castro Gutiérrez, Jimena, Baccile, Niki, Izquierdo Pantoja, María Teresa, Celzard, Alain, and Fierro, Vanessa

Abstract

In this study, efficient electrodes for the hydrogen evolution reaction (HER) based on low-cost and metal-free carbon catalysts are presented. Phytic acid, a biosourced molecule containing carbon (C) and phosphorus (P), was found to be an excellent precursor for producing carbon materials with high P content, depending on the carbonization temperature, from 27.9 wt% at 700 °C to 7.3 wt% at 1000 °C. A green and easy route to produce P-doped carbon materials by heat treatment of this biosourced precursor without the need for additional reagents is thus proposed. We show that the conversion of P-O-type groups into P-C-type species is of paramount importance for improving the catalytic activity in HER of P-doped carbon materials. P-C-type groups appear to be the key factor in the electrocatalytic activity, reaching an onset potential of - 0.27 V. This study sheds light on the origin of the catalytic activity of P-doped carbons, in which P is expected to modify the homogenous distribution of the electron density of undoped carbons and increase their catalytic performance.

Published
2023

55. Easy and support-free synthesis of bimetallic borates for boosting the oxygen evolution reaction

Author

Agence Nationale de la Recherche (France), European Commission, Ministerio de Universidades (España), Universidad de Oviedo, Universidad de Alicante, García Dalí, Sergio [0000-0002-0042-0430], Quílez Bermejo, J. [0000-0003-2808-1036], Karthik, Raj [0000-0002-8605-643X], Canevesi, Rafael L. S. [0000-0001-9076-1265], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Emo, Mélanie [0000-0003-3599-6824], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], García-Dalí, Sergio, Quílez Bermejo, J., Karthik, Raj, Canevesi, Rafael L. S., Izquierdo Pantoja, María Teresa, Emo, Mélanie, Celzard, Alain, Fierro, Vanessa, Agence Nationale de la Recherche (France), European Commission, Ministerio de Universidades (España), Universidad de Oviedo, Universidad de Alicante, García Dalí, Sergio [0000-0002-0042-0430], Quílez Bermejo, J. [0000-0003-2808-1036], Karthik, Raj [0000-0002-8605-643X], Canevesi, Rafael L. S. [0000-0001-9076-1265], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Emo, Mélanie [0000-0003-3599-6824], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], García-Dalí, Sergio, Quílez Bermejo, J., Karthik, Raj, Canevesi, Rafael L. S., Izquierdo Pantoja, María Teresa, Emo, Mélanie, Celzard, Alain, and Fierro, Vanessa

Abstract

The sluggish kinetics of the oxygen evolution reaction (OER) is one of the most limiting factors for the development of many “green” electrochemical devices. Expensive ruthenium and iridium oxide electrodes are often used as advanced electrocatalysts to overcome this limitation. However, these materials are rare in nature, which further limit the implementation of this kind of electrochemical device on a global scale. Compounds based on transition metals and boron have proven to be promising alternatives to commercial electrocatalysts due to their high catalytic properties and robust stability under working conditions. However, such compounds are often obtained through expensive synthetic routes that often involve the use of supports, which increases the cost of electrocatalysts. Here, we present an easy and support-free synthesis of bimetallic borates based on the introduction of transition metals into cobalt borates. Depending on the metal, different morphologies, structural order, surface chemistry, and, most importantly, electrocatalytic properties toward the OER have been obtained. Among all the transition metals, nickel is the one that most improves the catalytic activity of cobalt borate for the OER in an alkaline electrolyte. An overpotential of 230 mV, similar to that of commercial and state-of-the-art electrocatalysts, was obtained by using a support-free synthesis route for the preparation of this catalyst.

Published
2023

56. Advanced design of metal nanoclusters and single atoms embedded in C1N1-derived carbon materials for ORR, HER, and OER

Author

European Commission, Ministerio de Universidades (España), Universidad de Alicante, Universidad de Oviedo, Quílez Bermejo, J. [0000-0003-2808-1036], García Dalí, Sergio [0000-0002-0042-0430], Zitolo, Andrea [0000-0002-2187-6699], Canevesi, Rafael L. S. [0000-0001-9076-1265], Emo, Mélanie [0000-0003-3599-6824], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Badawi, Michael [0000-0002-3504-4180], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], Quílez Bermejo, J., García-Dalí, Sergio, Zitolo, Andrea, Canevesi, Rafael L. S., Emo, Mélanie, Izquierdo Pantoja, María Teresa, Badawi, Michael, Celzard, Alain, Fierro, Vanessa, European Commission, Ministerio de Universidades (España), Universidad de Alicante, Universidad de Oviedo, Quílez Bermejo, J. [0000-0003-2808-1036], García Dalí, Sergio [0000-0002-0042-0430], Zitolo, Andrea [0000-0002-2187-6699], Canevesi, Rafael L. S. [0000-0001-9076-1265], Emo, Mélanie [0000-0003-3599-6824], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Badawi, Michael [0000-0002-3504-4180], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], Quílez Bermejo, J., García-Dalí, Sergio, Zitolo, Andrea, Canevesi, Rafael L. S., Emo, Mélanie, Izquierdo Pantoja, María Teresa, Badawi, Michael, Celzard, Alain, and Fierro, Vanessa

Abstract

Single atoms and nanoclusters of Fe, Ni, Co, Cu, and Mn are systematically designed and embedded in a well-defined C1N1-type material that has internal cavities of ≈0.6 nm based on four N atoms. These N atoms serve as perfect anchoring points for the nucleation of small nanoclusters of different metal natures through the creation of metal-nitrogen (TM-N4) bonds. After pyrolysis at 800 °C, TM@CNx-type structures are obtained, where TM is the transition metal and x < 1. Fe@CNx and Co@CNx are the most promising for oxygen reduction reaction and hydrogen evolution reaction, respectively, with a Pt-like performance, and Ni@CNx is the most active for oxygen evolution reaction (OER) with an EOER of 1.59 V versus RHE, far outperforming the commercial IrO2 (EOER = 1.72 V). This systematic and benchmarking study can serve as a basis for the future design of advanced multi-functional electrocatalysts by modulating and combining the metallic nature of nanoclusters and single atoms.

Published
2023

57. Supporting information for Advanced design of metal nanoclusters and single atoms embedded in C1N1-derived carbon materials for ORR, HER, and OER [Dataset]

Author

Quílez Bermejo, J. [0000-0003-2808-1036], García Dalí, Sergio [0000-0002-0042-0430], Zitolo, Andrea [0000-0002-2187-6699], Canevesi, Rafael L. S. [0000-0001-9076-1265], Emo, Mélanie [0000-0003-3599-6824], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Badawi, Michael [0000-0002-3504-4180], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], Quílez Bermejo, J. [javier.quilez-bermejo@univ-lorraine.fr], Fierro, Vaessa [vanessa.fierro@univ-lorraine.fr], Quílez Bermejo, J., García-Dalí, Sergio, Zitolo, Andrea, Canevesi, Rafael L. S., Emo, Mélanie, Izquierdo Pantoja, María Teresa, Badawi, Michael, Celzard, Alain, Fierro, Vanessa, Quílez Bermejo, J. [0000-0003-2808-1036], García Dalí, Sergio [0000-0002-0042-0430], Zitolo, Andrea [0000-0002-2187-6699], Canevesi, Rafael L. S. [0000-0001-9076-1265], Emo, Mélanie [0000-0003-3599-6824], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Badawi, Michael [0000-0002-3504-4180], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], Quílez Bermejo, J. [javier.quilez-bermejo@univ-lorraine.fr], Fierro, Vaessa [vanessa.fierro@univ-lorraine.fr], Quílez Bermejo, J., García-Dalí, Sergio, Zitolo, Andrea, Canevesi, Rafael L. S., Emo, Mélanie, Izquierdo Pantoja, María Teresa, Badawi, Michael, Celzard, Alain, and Fierro, Vanessa

Abstract

1. Stability of the G−N4−TM structures.-- 2. O2 Interaction with the Fe–N4 Center.-- 3. Calculation methods of evaluating ORR, OER and HER activity.-- 4. Density of states calculations.-- Supplementary Figures and Tables

Published
2023

58. Supporting information of Catalyzing sustainability: phytic acid as a green precursor for metal-free carbon electrocatalysts in ORR [Dataset]

Author

Agence Nationale de la Recherche (France), European Commission, Ministerio de Universidades (España), Universidad de Oviedo, García Dalí, Sergio [0000-0002-0042-0430], Quílez Bermejo, J. [0000-0003-2808-1036], Castro Gutiérrez, Jimena [0000-0002-6319-2498], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], Fierro, Vanessa [Vanessa.Fierro@univ-lorraine.fr], García Dalí, Sergio, Quílez Bermejo, J., Castro Gutiérrez, Jimena, Izquierdo Pantoja, María Teresa, Celzard, Alain, Fierro, Vanessa, Agence Nationale de la Recherche (France), European Commission, Ministerio de Universidades (España), Universidad de Oviedo, García Dalí, Sergio [0000-0002-0042-0430], Quílez Bermejo, J. [0000-0003-2808-1036], Castro Gutiérrez, Jimena [0000-0002-6319-2498], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], Fierro, Vanessa [Vanessa.Fierro@univ-lorraine.fr], García Dalí, Sergio, Quílez Bermejo, J., Castro Gutiérrez, Jimena, Izquierdo Pantoja, María Teresa, Celzard, Alain, and Fierro, Vanessa

Abstract

Figure S1: Pore size distributions of all PDC-T samples. Table S1: Atomic percentages (at.%) of carbon (C), oxygen (O) and phosphorus (P), obtained by XPS, and ratios of P-C bonds to total P (PT) content for all PDC-T materials. Figure S2: XPS spectra of (a) C 1s and (b) O 1s of the PDC-T series. Table S2: Literature comparison of the performance of materials similar to PDC-900 for the ORR shown in Fig. 4f.

Published
2023

59. Catalyzing sustainability: phytic acid as a green precursor for metal-free carbon electrocatalysts in ORR

Author

Agence Nationale de la Recherche (France), European Commission, Ministerio de Universidades (España), Universidad de Oviedo, García Dalí, Sergio [0000-0002-0042-0430], Quílez Bermejo, J. [0000-0003-2808-1036], Castro Gutiérrez, Jimena [0000-0002-6319-2498], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], Fierro, Vanessa [Vanessa.Fierro@univ-lorraine.fr], García Dalí, Sergio, Quílez Bermejo, J., Castro Gutiérrez, Jimena, Izquierdo Pantoja, María Teresa, Celzard, Alain, Fierro, Vanessa, Agence Nationale de la Recherche (France), European Commission, Ministerio de Universidades (España), Universidad de Oviedo, García Dalí, Sergio [0000-0002-0042-0430], Quílez Bermejo, J. [0000-0003-2808-1036], Castro Gutiérrez, Jimena [0000-0002-6319-2498], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], Fierro, Vanessa [Vanessa.Fierro@univ-lorraine.fr], García Dalí, Sergio, Quílez Bermejo, J., Castro Gutiérrez, Jimena, Izquierdo Pantoja, María Teresa, Celzard, Alain, and Fierro, Vanessa

Abstract

The sluggish kinetics and high overpotential of the oxygen reduction reaction (ORR) in fuel cells and metal–air batteries are currently resolved through the use of expensive and scarce platinum-based electrocatalysts. Here, a green and straightforward synthesis method for preparing metal-free phosphorus-doped carbon (PDC) materials via carbonization of phytic acid at temperatures ranging from 700 to 1000 °C is reported. This study provides valuable insights into the effect of carbonization temperature on the surface chemistry and catalytic performance of PDCs. The PDC electrocatalysts exhibit ORR electrocatalytic activity equivalent to that of the state-of-the-art P-doped carbons and show a correlation between the content of C–P species and the electrocatalytic activity for the ORR. The study suggests that C–P-type species are responsible for the improved ORR. These findings not only demonstrate a practical and low-cost approach for preparing highly efficient metal-free electrocatalysts for the ORR, but also highlight their potential for the development of sustainable energy technologies.

Published
2023

61. Dielectric and Ultrasonic Properties of PDMS/TiO 2 Nanocomposites.

Author

Vanskeviče, Ieva, Kinka, Martynas, Banys, Jūras, Macutkevič, Jan, Schaefer, Sebastien, Selskis, Algirdas, Fierro, Vanessa, and Celzard, Alain

Subjects
DIELECTRIC properties, ULTRASONIC wave attenuation, TITANIUM dioxide nanoparticles, TITANIUM dioxide, POLYDIMETHYLSILOXANE, GARNET, NANOCOMPOSITE materials
Abstract

This work presents the dielectric and ultrasonic properties of polydimethylsiloxane (PDMS) nanocomposites filled with titanium dioxide nanoparticles. The dielectric study was performed over a very broad range of frequencies (20 Hz–3 THz). The dielectric permittivity was almost frequency-independent in all the composites at room temperature over the whole range of measurement frequencies, and the dielectric losses were very low under these conditions (less than 2). The dielectric permittivity strongly increases with the nanoparticle concentration according to the Maxwell–Garnet model. Therefore, the investigated composites are suitable for various flexible electronic applications, particularly in the microwave and terahertz frequency ranges. Dielectric dispersion and increased attenuation of ultrasonic waves were observed at lower temperatures (below 280 K) due to the relaxation of polymer molecules at the PDMS/TiO2 interface and in the polymer matrix. The relaxation time followed the Vogel–Vulcher law, while the freezing temperature increased with the titanium dioxide concentration due to interactions between the polymer molecules and nanoparticles. The significant hysteresis in the ultrasonic properties indicated that titanium dioxide acts as a crystallization center. This is confirmed by the correlation between the hysteresis in the ultrasonic properties and the structure of the composites. The small difference in the activation energy values obtained from the ultrasonic and dielectric investigations is related to the fact that the dielectric dispersion is slightly broader than the Debye-type dielectric dispersion. [ABSTRACT FROM AUTHOR]

Published
2024
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64. Adsorption of Model Dyes Onto Porous Materials: Effect of pH and Temperature on the Parameters of Brouers-Sotolongo Kinetic Fractal and Generalized Isotherm

Author

Selmi, Taher, Seffen, Mongi, Brouers, François, Fierro, Vanessa, Sammouda, Habib, Abdalla, Hassan, Series editor, Abdul Mannan, Md., Series editor, Alalouch, Chaham, Series editor, Attia, Sahar, Series editor, Boemi, Sofia Natalia, Series editor, Bougdah, Hocine, Series editor, Bozonnet, Emmanuel, Series editor, De Bonis, Luciano, Series editor, Hawkes, Dean, Series editor, Kostopoulou, Stella, Series editor, Mahgoub, Yasser, Series editor, Mesbah Elkaffas, Saleh, Series editor, Mohareb, Nabil, Series editor, O. Gawad, Iman, Series editor, Oostra, Mieke, Series editor, Pignatta, Gloria, Series editor, Pisello, Anna Laura, Series editor, Rosso, Federica, Series editor, Kallel, Amjad, editor, Ksibi, Mohamed, editor, Ben Dhia, Hamed, editor, and Khélifi, Nabil, editor

Published
2018
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72. Contributors

Author

Bagci, Hakan, primary, Bondar, Vladimir S., additional, Celzard, Alain, additional, Chen, Pai-Yen, additional, D’Aloia, Alessandro Giuseppe, additional, D'Amore, Marcello, additional, Farhat, Mohamed, additional, Fierro, Vanessa, additional, Hanson, George, additional, Hartmann, R.R., additional, Kaplas, Tommi, additional, Kuzhir, Polina, additional, Lambin, Philippe, additional, Letellier, Maxime, additional, Lobet, Michaël, additional, Low, Tony, additional, Macutkevic, Jan, additional, Maffucci, Antonio, additional, Majérus, Bruno, additional, Maksimenko, Sergey, additional, Mikheev, Gennady M., additional, Mogileva, Tatyana N., additional, Nemilentsau, Andrei, additional, Paddubskaya, Alesia, additional, Portnoi, M.E., additional, Puzyr, Alexey P., additional, Sakhdari, Maryam, additional, Saroka, V.A., additional, Sarto, Maria Sabrina, additional, Shuba, Mikhail V., additional, Slepyan, Gregory Y., additional, Svirko, Yuri P., additional, and Vanyukov, Viatcheslav V., additional

Published
2019
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73. Electromagnetics of carbon: Nano versus micro

Author

Kuzhir, Polina, primary, Paddubskaya, Alesia, additional, Macutkevic, Jan, additional, Letellier, Maxime, additional, Celzard, Alain, additional, Fierro, Vanessa, additional, Kaplas, Tommi, additional, and Svirko, Yuri P., additional

Published
2019
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74. Organic and Carbon Gels

Author

Arenillas, Ana, primary, Menéndez, J. Angel, additional, Reichenauer, Gudrun, additional, Celzard, Alain, additional, Fierro, Vanessa, additional, Maldonado Hodar, Francisco José, additional, Bailόn-Garcia, Esther, additional, and Job, Nathalie, additional

Published
2019
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75. Supplementary material for Zinc doping enhances the electrocatalytic properties of cobalt borides for the hydrogen evolution reaction [Dataset]

Author

Ministerio de Universidades (España), European Commission, Universidad de Alicante, Universidad de Oviedo, Agence Nationale de la Recherche (France), Quílez Bermejo, J. [0000-0003-2808-1036], García Dalí, Sergio [0000-0002-0042-0430], Karthik, Raj [0000-0002-8605-643X], Canevesi, Rafael L. S. [0000-0001-9076-1265], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Emo, Mélanie [0000-0003-3599-6824], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], Quílez Bermejo, J.; Fierro, Vanessa, Quílez Bermejo, J., García-Dalí, Sergio, Karthik, Raj, Canevesi, Rafael L. S., Izquierdo Pantoja, María Teresa, Emo, Mélanie, Celzard, Alain, Fierro, Vanessa, Ministerio de Universidades (España), European Commission, Universidad de Alicante, Universidad de Oviedo, Agence Nationale de la Recherche (France), Quílez Bermejo, J. [0000-0003-2808-1036], García Dalí, Sergio [0000-0002-0042-0430], Karthik, Raj [0000-0002-8605-643X], Canevesi, Rafael L. S. [0000-0001-9076-1265], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Emo, Mélanie [0000-0003-3599-6824], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], Quílez Bermejo, J.; Fierro, Vanessa, Quílez Bermejo, J., García-Dalí, Sergio, Karthik, Raj, Canevesi, Rafael L. S., Izquierdo Pantoja, María Teresa, Emo, Mélanie, Celzard, Alain, and Fierro, Vanessa

Abstract

Figure S1: EDS of (a) Co-B and (b) Co-Zn-B. Figure S2 : Particle size distribution of Co-B and Co-Zn-B. Figure S3 : CV pre and post HER of Co-Zn-B at a scan rate of 50 mV·s-1 in a N2-saturated 0.1 M KOH solution. Figure S4: Chronopotentiometric analysis of Co-Zn-B sample at a fixed current density of -5 mA·cm-2.

Published
2022

76. CO2 outperforms KOH as an activator for high-rate supercapacitors in aqueous electrolyte

Author

Consejo Nacional de Ciencia y Tecnología (México), Secretaría de Energía (México), Université de Lorraine (France), European Commission, Castro Gutiérrez, Jimena [0000-0002-6319-2498], Canevesi, Rafael L. S. [0000-0001-9076-1265], Emo, Mélanie [0000-0003-3599-6824], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], Castro Gutiérrez, Jimena, Canevesi, Rafael L. S., Emo, Mélanie, Izquierdo Pantoja, María Teresa, Celzard, Alain, Fierro, Vanessa, Consejo Nacional de Ciencia y Tecnología (México), Secretaría de Energía (México), Université de Lorraine (France), European Commission, Castro Gutiérrez, Jimena [0000-0002-6319-2498], Canevesi, Rafael L. S. [0000-0001-9076-1265], Emo, Mélanie [0000-0003-3599-6824], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], Castro Gutiérrez, Jimena, Canevesi, Rafael L. S., Emo, Mélanie, Izquierdo Pantoja, María Teresa, Celzard, Alain, and Fierro, Vanessa

Abstract

Although high-surface area activated carbons used as supercapacitor (SC) electrodes are frequently produced by KOH activation, this study shows that, when aqueous electrolytes are used, CO2 activation is a better choice from the point of view of SC performance, environment and economy. Ordered mesoporous carbons (OMCs) produced by a mechanochemical synthesis method from mimosa tannin are activated with KOH to use these materials as electrodes for SCs. A comparative analysis of the same OMCs but activated with CO2 is presented to examine the effect of the activation process on materials performance. KOH-activated materials exhibit good electrochemical performance at low charging rates, reaching specific cell capacitance values of 49 F g−1 at 0.5 Ag−1, however, restricted access to microporosity and low water affinity water reduces their performance at high charging rates. In contrast, the best performing CO2-activated material can retain 81% of capacitance at 20 A g−1, compared to 25% for a KOH-activated OMC with similar properties and tested under the same conditions. A thorough review of the open literature suggests that CO2 activation would produce materials with a suitable combination of pore network connectivity and water affinity, resulting in SCs with high rate capability in an aqueous electrolyte. These conclusions were drawn by judiciously integrating the analysis of: (i) the hysteresis loop scanning of N2 adsorption-desorption isotherms; and (ii) water adsorption isotherms as tools to more accurately assess the pore network connectivity and water affinity of the materials, which are not generally considered when studying SC performance.

Published
2022

77. Zinc doping enhances the electrocatalytic properties of cobalt borides for the hydrogen evolution reaction

Author

Ministerio de Universidades (España), European Commission, Universidad de Alicante, Universidad de Oviedo, Agence Nationale de la Recherche (France), Quílez Bermejo, J. [0000-0003-2808-1036], García Dalí, Sergio [0000-0002-0042-0430], Karthik, Raj [0000-0002-8605-643X], Canevesi, Rafael L. S. [0000-0001-9076-1265], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Emo, Mélanie [0000-0003-3599-6824], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], Quílez Bermejo, J., García-Dalí, Sergio, Karthik, Raj, Canevesi, Rafael L. S., Izquierdo Pantoja, María Teresa, Emo, Mélanie, Celzard, Alain, Fierro, Vanessa, Ministerio de Universidades (España), European Commission, Universidad de Alicante, Universidad de Oviedo, Agence Nationale de la Recherche (France), Quílez Bermejo, J. [0000-0003-2808-1036], García Dalí, Sergio [0000-0002-0042-0430], Karthik, Raj [0000-0002-8605-643X], Canevesi, Rafael L. S. [0000-0001-9076-1265], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Emo, Mélanie [0000-0003-3599-6824], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], Quílez Bermejo, J., García-Dalí, Sergio, Karthik, Raj, Canevesi, Rafael L. S., Izquierdo Pantoja, María Teresa, Emo, Mélanie, Celzard, Alain, and Fierro, Vanessa

Abstract

Electrochemical water splitting requires new, low-cost cathode electrodes for the hydrogen evolution reaction to enable the worldwide implementation of electrolyzers. Cobalt borides are proposed as one of the most promising materials to overcome the limitations of the commercial electrocatalysts, but the catalytic activity still needs to be improved to be competitive. Here, we report that the introduction of zinc into cobalt boride to produce a ternary cobalt boride is an efficient route to further improve the catalytic activity towards the hydrogen evolution reaction (HER) of cobalt boride. The ternary Co-Zn-B was prepared by an easy chemical reduction method to achieve superior HER electrocatalytic performance with a lower overpotential than the homologous Co-B. The larger surface area, structural order, crystallization degree and, in particular, the different surface chemistry seem to be key factors for this improvement.

Published
2022

78. Roles of surface chemistry and texture of nanoporous activated carbons in CO2 capture

Author

Agence Nationale de la Recherche (France), European Commission, Canevesi, Rafael L. S. [0000-0001-9076-1265], Schaefer, Sébastien [0000-0002-6299-0340], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], Canevesi, Rafael L. S., Schaefer, Sébastien, Izquierdo Pantoja, María Teresa, Celzard, Alain, Fierro, Vanessa, Agence Nationale de la Recherche (France), European Commission, Canevesi, Rafael L. S. [0000-0001-9076-1265], Schaefer, Sébastien [0000-0002-6299-0340], Izquierdo Pantoja, María Teresa [0000-0002-2408-2528], Celzard, Alain [0000-0003-0073-9545], Fierro, Vanessa [0000-0001-7081-3697], Canevesi, Rafael L. S., Schaefer, Sébastien, Izquierdo Pantoja, María Teresa, Celzard, Alain, and Fierro, Vanessa

Abstract

The presence of heteroatoms, such as nitrogen or oxygen, on the surface of nanoporous activated carbons (ACs) promotes CO2 uptake due to the stronger specific interactions with these heteroatoms. However, heteroatom doping post-treatments often decrease the surface area and pore volume of ACs, and it is difficult to separate heteroatom doping from textural effects. The objective of this paper was to investigate when the control of adsorption shifts from surface chemistry to textural characteristics. For this purpose, three different types of commercial ACs were doped with nitrogen and/or oxygen by an easy and cheap method and then subjected to CO2 adsorption experiments up to 32 bar at 273 K. We evaluated the effect of the surface chemistry and texture, considering the whole range of porosity on CO2 adsorption as a function of pressure. Below atmospheric pressure, CO2 adsorption is mainly controlled by surface chemistry, increasing with O + N content, and the narrowest pores are responsible for more than 60% of CO2 adsorption at pressures below 0.01 bar. Above atmospheric pressure, from 1 to about 5 bar, the textural properties become more significant to finally take control of the adsorption phenomena at pressures above 5 bar. We have undoubtedly shown that the adsorption capacity is only a function of the total pore volume and that the adsorbed density is even higher than that of liquid CO2 in ultramicropores (pore diameter less than 0.7 nm) at pressures of 15 bar and above.

Published
2022

82. Piezoelectric Nanogenerators Based On BaTiO3/PDMS Composites for High-Frequency Applications

Author

Meisak, Darya, primary, Kinka, Martynas, additional, Plyushch, Artyom, additional, Macutkevič, Jan, additional, Zarkov, Aleksej, additional, Schaefer, Sébastien, additional, Selskis, Algirdas, additional, Samulionis, Vytautas, additional, Kuzhir, Polina, additional, Banys, Ju̅ras, additional, Fierro, Vanessa, additional, and Celzard, Alain, additional

Published
2023
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85. Green and easy synthesis of P-doped carbon-based hydrogen evolution reaction electrocatalysts

Author

Universidad de Alicante. Departamento de Química Inorgánica, Universidad de Alicante. Instituto Universitario de Materiales, García-Dalí, Sergio, Quílez-Bermejo, Javier, Castro-Gutiérrez, Jimena, Baccile, Niki, Izquierdo, María T., Celzard, Alain, Fierro, Vanessa, Universidad de Alicante. Departamento de Química Inorgánica, Universidad de Alicante. Instituto Universitario de Materiales, García-Dalí, Sergio, Quílez-Bermejo, Javier, Castro-Gutiérrez, Jimena, Baccile, Niki, Izquierdo, María T., Celzard, Alain, and Fierro, Vanessa

Abstract

In this study, efficient electrodes for the hydrogen evolution reaction (HER) based on low-cost and metal-free carbon catalysts are presented. Phytic acid, a biosourced molecule containing carbon (C) and phosphorus (P), was found to be an excellent precursor for producing carbon materials with high P content, depending on the carbonization temperature, from 27.9 wt.% at 700 °C to 7.3 wt.% at 1000 °C. A green and easy route to produce P-doped carbon materials by heat treatment of this biosourced precursor without the need for additional reagents is thus proposed. We show that the conversion of P-O-type groups into P-C-type species is of paramount importance for improving the catalytic activity in HER of P-doped carbon materials. P-C-type groups appear to be the key factor in the electrocatalytic activity, reaching an onset potential of - 0.27 V. This study sheds light on the origin of the catalytic activity of P-doped carbons, in which P is expected to modify the homogenous distribution of the electron density of undoped carbons and increase their catalytic performance.

Published
2023

86. Nitrogen sites prevail over textural properties in N-doped carbons for the oxygen reduction reaction

Author

Universidad de Alicante. Departamento de Química Inorgánica, Universidad de Alicante. Departamento de Química Física, Universidad de Alicante. Instituto Universitario de Materiales, Quílez-Bermejo, Javier, Pérez-Rodríguez, Sara, Torres, Daniel, Canevesi, Rafael L.S., Morallon, Emilia, Cazorla-Amorós, Diego, Celzard, Alain, Fierro, Vanessa, Universidad de Alicante. Departamento de Química Inorgánica, Universidad de Alicante. Departamento de Química Física, Universidad de Alicante. Instituto Universitario de Materiales, Quílez-Bermejo, Javier, Pérez-Rodríguez, Sara, Torres, Daniel, Canevesi, Rafael L.S., Morallon, Emilia, Cazorla-Amorós, Diego, Celzard, Alain, and Fierro, Vanessa

Abstract

Nitrogen-doped carbon-based electrodes are among the most promising alternatives to platinum-based electrodes in the cathode of fuel cells and metal-air batteries, where the oxygen reduction reaction (ORR) takes place. Among the approaches for improving ORR activity, nitrogen functionalities and well-developed textural properties have proved very effective. Nonetheless, the question of which between nitrogen active sites or textural properties are more crucial in N-doped carbon materials remains unanswered. This work proposes a comparative and critical approach through the selective functionalization of four commercial activated carbons with different textural properties. This study highlights the greater importance of N-doping in relation to the textural properties of carbon materials, and provides fundamental insights for conclusively addressing the ongoing debate within the carbon community about the significance of these two factors in the context of ORR.

Published
2023

87. Easy and Support-Free Synthesis of Bimetallic Borates for Boosting the Oxygen Evolution Reaction

Author

Universidad de Alicante. Departamento de Química Inorgánica, Universidad de Alicante. Instituto Universitario de Materiales, García-Dalí, Sergio, Quílez-Bermejo, Javier, Karthik, Raj, Canevesi, Rafael L.S., Izquierdo, María T., Emo, Mélanie, Celzard, Alain, Fierro, Vanessa, Universidad de Alicante. Departamento de Química Inorgánica, Universidad de Alicante. Instituto Universitario de Materiales, García-Dalí, Sergio, Quílez-Bermejo, Javier, Karthik, Raj, Canevesi, Rafael L.S., Izquierdo, María T., Emo, Mélanie, Celzard, Alain, and Fierro, Vanessa

Abstract

The sluggish kinetics of the oxygen evolution reaction (OER) is one of the most limiting factors for the development of many “green” electrochemical devices. Expensive ruthenium and iridium oxide electrodes are often used as advanced electrocatalysts to overcome this limitation. However, these materials are rare in nature, which further limit the implementation of this kind of electrochemical device on a global scale. Compounds based on transition metals and boron have proven to be promising alternatives to commercial electrocatalysts due to their high catalytic properties and robust stability under working conditions. However, such compounds are often obtained through expensive synthetic routes that often involve the use of supports, which increases the cost of electrocatalysts. Here, we present an easy and support-free synthesis of bimetallic borates based on the introduction of transition metals into cobalt borates. Depending on the metal, different morphologies, structural order, surface chemistry, and, most importantly, electrocatalytic properties toward the OER have been obtained. Among all the transition metals, nickel is the one that most improves the catalytic activity of cobalt borate for the OER in an alkaline electrolyte. An overpotential of 230 mV, similar to that of commercial and state-of-the-art electrocatalysts, was obtained by using a support-free synthesis route for the preparation of this catalyst.

Published
2023

91. Biomass Derived High Porous Carbon via CO 2 Activation for Supercapacitor Electrodes.

Author

Taurbekov, Azamat, Abdisattar, Alisher, Atamanov, Meiram, Yeleuov, Mukhtar, Daulbayev, Chingis, Askaruly, Kydyr, Kaidar, Bayan, Mansurov, Zulkhair, Castro-Gutierrez, Jimena, Celzard, Alain, Fierro, Vanessa, and Atamanova, Tolganay

Subjects
CARBON dioxide, CLEAN energy, ACTIVATION (Chemistry), ENERGY storage, ACTIVATED carbon, SUPERCAPACITOR electrodes
Abstract

In this study, we systematically study the efficient production method and electrochemical characteristics of activated carbons (AC) derived from rice husk (RH) and walnut shell (WS). In particular, the effectiveness of physical activation using carbon dioxide (CO2) was investigated and compared with the more common chemical activation method using potassium hydroxide (KOH). The results show that the KOH–activated samples have remarkable specific capacities, reaching 157.8 F g−1 for RH and 152 F g−1 for WS at 1 A g−1. However, the rate capability of AC obtained via KOH decreases significantly as the scanning rate increases, retaining only 51.5% and 68% of their original capacities for RH–KOH and WS–KOH, respectively, at 20 A g–1. In contrast, CO2–activated samples show a superior rate performance with a capacity retention of 75.6% for WS and 80% for RH at the same current density. In addition, electrochemical impedance spectroscopy (EIS) analysis shows that AC obtained via CO2 has a lower charge transfer resistance compared to its KOH counterparts. CO2–activated RH and WS electrodes show Rct values of 0.1 Ω and 0.24 Ω, respectively, indicating improved ion transport kinetics and surface area utilization. These results highlight the importance of activation techniques in tailoring the electrochemical behavior of biomass–derived carbon. This study not only expands the understanding of the interaction between activation, morphology, and performance but also indicates the potential of CO2 activation as an environmentally friendly and efficient alternative. As the field of sustainable energy storage advances, this work provides valuable guidance for the development of high–performance supercapacitor electrodes with less environmental impact. [ABSTRACT FROM AUTHOR]

Published
2023
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