Pub Date : 2025-02-10DOI: 10.1016/j.mtcata.2025.100091
Ting Wai Lau , Qiong Lei , Jun Yin
The design of highly efficient hydrogen evolution reaction (HER) catalysts is a critical challenge in advancing electrochemical water splitting for renewable energy applications. Topological semimetals have recently emerged as promising candidates for HER catalysis; however, the relationship between their topological surface properties and catalytic performance remains poorly understood. Herein, we employ density functional theory (DFT) calculations to investigate the impact of facets on the HER activity of topological TaAs semimetal family (TaAs, NbP, NbAs, and TaP). Our results reveal that topological surface states persist across various facets, and facets with lower coordination numbers exhibit greater stability. Four key theoretical descriptors—Gibbs free energy changes, surface energy, energy barriers for water dissociation, and water adsorption energy—are assessed to provide a comprehensive evaluation of HER activity. For all four compounds, (111) and metal-rich (001) facets exhibit optimal energy values across these metrics, outperforming the benchmark Pt (111). The number of Fermi arcs is found to have a minimal influence on HER activity. Changes in the projected density of states (PDOS) of surface atoms strongly correlate with ΔGH*, serving as a more effective indicator of HER activity. These findings highlight the importance of a holistic evaluation framework that extends beyond Gibbs free energy changes alone, incorporating multiple factors to identify high-performance catalysts. This work provides new insights into the design principles for topological catalysts in HER and offers valuable guidance for developing next generation of electrocatalysts.
{"title":"Facet engineering of Weyl semimetals for efficient hydrogen evolution reaction","authors":"Ting Wai Lau , Qiong Lei , Jun Yin","doi":"10.1016/j.mtcata.2025.100091","DOIUrl":"10.1016/j.mtcata.2025.100091","url":null,"abstract":"<div><div>The design of highly efficient hydrogen evolution reaction (HER) catalysts is a critical challenge in advancing electrochemical water splitting for renewable energy applications. Topological semimetals have recently emerged as promising candidates for HER catalysis; however, the relationship between their topological surface properties and catalytic performance remains poorly understood. Herein, we employ density functional theory (DFT) calculations to investigate the impact of facets on the HER activity of topological TaAs semimetal family (TaAs, NbP, NbAs, and TaP). Our results reveal that topological surface states persist across various facets, and facets with lower coordination numbers exhibit greater stability. Four key theoretical descriptors—Gibbs free energy changes, surface energy, energy barriers for water dissociation, and water adsorption energy—are assessed to provide a comprehensive evaluation of HER activity. For all four compounds, (111) and metal-rich (001) facets exhibit optimal energy values across these metrics, outperforming the benchmark Pt (111). The number of Fermi arcs is found to have a minimal influence on HER activity. Changes in the projected density of states (PDOS) of surface atoms strongly correlate with Δ<em>G</em><sub>H*</sub>, serving as a more effective indicator of HER activity. These findings highlight the importance of a holistic evaluation framework that extends beyond Gibbs free energy changes alone, incorporating multiple factors to identify high-performance catalysts. This work provides new insights into the design principles for topological catalysts in HER and offers valuable guidance for developing next generation of electrocatalysts.</div></div>","PeriodicalId":100892,"journal":{"name":"Materials Today Catalysis","volume":"8 ","pages":"Article 100091"},"PeriodicalIF":0.0,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-07DOI: 10.1016/j.mtcata.2025.100090
Kang Huang , Zhixiu Lu , Shilong Dai , Chunyu Cui , Nam Dong Kim , Huilong Fei
Cycling Li-O2 batteries (LOBs) via LiOH is promising for developing practically viable batteries, while promoting the formation and decomposition of LiOH remains a challenge. Cobalt single atom catalysts (Co-SACs) have been exploited to mediate the direct 4e− oxygen reduction reaction for generating LiOH discharge products, but their inferior oxygen evolution activity renders the battery low energy efficiency and poor cycling life. Herein, we for the first time introduce LiBr redox mediator (RM) into the Co-SACs-catalyzed LOB system to facilitate the decomposition of LiOH. In the discharge process, the catalysis of Co-SAC is unaffected with the presence of LiBr. During charging, Br3− is identified as the oxidizer to decompose LiOH at an appropriate potential (3.6 V). Significantly, the soluble Br− is recyclable in the system as the BrO− intermediate could shuttle to the anode and react with Li metal to regenerate Br− so that the generation of LiBrO3 deposit is circumvented. Consequently, the fabricated LOB demonstrates fewer side reactions, stable energy efficiency (drop rate of 0.10 % per cycle) and long cycle life (300 cycles at 1000 mA/g) under the ambient atmosphere.
{"title":"Coupling cobalt single-atom catalyst with recyclable LiBr redox mediator enables stable LiOH-based Li-O2 batteries","authors":"Kang Huang , Zhixiu Lu , Shilong Dai , Chunyu Cui , Nam Dong Kim , Huilong Fei","doi":"10.1016/j.mtcata.2025.100090","DOIUrl":"10.1016/j.mtcata.2025.100090","url":null,"abstract":"<div><div>Cycling Li-O<sub>2</sub> batteries (LOBs) via LiOH is promising for developing practically viable batteries, while promoting the formation and decomposition of LiOH remains a challenge. Cobalt single atom catalysts (Co-SACs) have been exploited to mediate the direct 4e<sup>−</sup> oxygen reduction reaction for generating LiOH discharge products, but their inferior oxygen evolution activity renders the battery low energy efficiency and poor cycling life. Herein, we for the first time introduce LiBr redox mediator (RM) into the Co-SACs-catalyzed LOB system to facilitate the decomposition of LiOH. In the discharge process, the catalysis of Co-SAC is unaffected with the presence of LiBr. During charging, Br<sub>3</sub><sup>−</sup> is identified as the oxidizer to decompose LiOH at an appropriate potential (3.6 V). Significantly, the soluble Br<sup>−</sup> is recyclable in the system as the BrO<sup>−</sup> intermediate could shuttle to the anode and react with Li metal to regenerate Br<sup>−</sup> so that the generation of LiBrO<sub>3</sub> deposit is circumvented. Consequently, the fabricated LOB demonstrates fewer side reactions, stable energy efficiency (drop rate of 0.10 % per cycle) and long cycle life (300 cycles at 1000 mA/g) under the ambient atmosphere.</div></div>","PeriodicalId":100892,"journal":{"name":"Materials Today Catalysis","volume":"8 ","pages":"Article 100090"},"PeriodicalIF":0.0,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143378854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-06DOI: 10.1016/j.mtcata.2025.100089
Dazhi Yao , Chun Liu , Yanzhao Zhang , Shuhao Wang , Yan Nie , Man Qiao , Dongdong Zhu
Direct seawater electrolysis (DSE) has emerged as a compelling route to sustainable hydrogen production, leveraging the vast global reserves of seawater. However, the inherently complex composition of seawater—laden with halide ions, multivalent cations (Mg2+, Ca2+), and organic/biological impurities—presents formidable challenges in maintaining both selectivity and durability. Chief among these obstacles is mitigating chloride corrosion and suppressing chlorine evolution reaction (ClER) at the anode, while also preventing the precipitation of magnesium and calcium hydroxides at the cathode. This review consolidates recent advances in material engineering and cell design strategies aimed at controlling undesired side reactions, enhancing electrode stability, and maximizing energy efficiency in DSE. We first outline the fundamental thermodynamic and kinetic hurdles introduced by Cl− and other impurities. This discussion highlights how these factors accelerate catalyst degradation and drive suboptimal reaction pathways. We then delve into innovative approaches to improve selectivity and durability of DSE—such as engineering protective barrier layers, tuning electrolyte interfaces, developing corrosion-resistant materials, and techniques to minimize Mg/Ca-related precipitations. Finally, we explore emerging reactor configurations, including asymmetric and membrane-free electrolyzers, which address some barriers for DSE commercialization. Collectively, these insights provide a framework for designing next-generation DSE systems, which can achieve large-scale, cost-effective, and environmentally benign hydrogen production.
{"title":"Modulating selectivity and stability of the direct seawater electrolysis for sustainable green hydrogen production","authors":"Dazhi Yao , Chun Liu , Yanzhao Zhang , Shuhao Wang , Yan Nie , Man Qiao , Dongdong Zhu","doi":"10.1016/j.mtcata.2025.100089","DOIUrl":"10.1016/j.mtcata.2025.100089","url":null,"abstract":"<div><div>Direct seawater electrolysis (DSE) has emerged as a compelling route to sustainable hydrogen production, leveraging the vast global reserves of seawater. However, the inherently complex composition of seawater—laden with halide ions, multivalent cations (Mg<sup>2</sup><sup>+</sup>, Ca<sup>2+</sup>), and organic/biological impurities—presents formidable challenges in maintaining both selectivity and durability. Chief among these obstacles is mitigating chloride corrosion and suppressing chlorine evolution reaction (ClER) at the anode, while also preventing the precipitation of magnesium and calcium hydroxides at the cathode. This review consolidates recent advances in material engineering and cell design strategies aimed at controlling undesired side reactions, enhancing electrode stability, and maximizing energy efficiency in DSE. We first outline the fundamental thermodynamic and kinetic hurdles introduced by Cl<sup>−</sup> and other impurities. This discussion highlights how these factors accelerate catalyst degradation and drive suboptimal reaction pathways. We then delve into innovative approaches to improve selectivity and durability of DSE—such as engineering protective barrier layers, tuning electrolyte interfaces, developing corrosion-resistant materials, and techniques to minimize Mg/Ca-related precipitations. Finally, we explore emerging reactor configurations, including asymmetric and membrane-free electrolyzers, which address some barriers for DSE commercialization. Collectively, these insights provide a framework for designing next-generation DSE systems, which can achieve large-scale, cost-effective, and environmentally benign hydrogen production.</div></div>","PeriodicalId":100892,"journal":{"name":"Materials Today Catalysis","volume":"8 ","pages":"Article 100089"},"PeriodicalIF":0.0,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-31DOI: 10.1016/j.mtcata.2024.100086
Ruonan Liu , Yaotian Yan , Liang Dun , Taili Yang , Bin Qin , Peijia Wang , Wei Cai , Shude Liu , Xiaohang Zheng
Transition metal oxides hold great potential for water splitting due to their tunable electronic structures and abundant availability. However, their inherently poor electrical conductivity and limited catalytic activity hinder their practical implementation. Herein, high-entropy oxide (FeCoNiCrCuO) electrocatalysts featuring grain-like structure and oxygen vacancies-enriched surface were synthesized through an ultra-fast non-equilibrium high-temperature shock. The introduction of oxygen vacancies modulates the electronic structure and increases the carrier concentration, accelerating the rate-determining step of the oxygen evolution reactions and reducing the overpotential of oxygen evolution reactions. Consequently, the synthesized FeCoNiCrCuO electrocatalyst delivers a low overpotential of 256 mV at a current density of 10 mA·cm⁻² and a Tafel slope of 48.2 mV·dec⁻¹ in 1 M KOH, which is superior to samples lacking oxygen vacancies after annealing. This study presents an alternative approach to enhancing OER activity by employing a high-entropy oxide engineering strategy.
{"title":"Oxygen vacancy-mediated high-entropy oxide electrocatalysts for efficient oxygen evolution reaction","authors":"Ruonan Liu , Yaotian Yan , Liang Dun , Taili Yang , Bin Qin , Peijia Wang , Wei Cai , Shude Liu , Xiaohang Zheng","doi":"10.1016/j.mtcata.2024.100086","DOIUrl":"10.1016/j.mtcata.2024.100086","url":null,"abstract":"<div><div>Transition metal oxides hold great potential for water splitting due to their tunable electronic structures and abundant availability. However, their inherently poor electrical conductivity and limited catalytic activity hinder their practical implementation. Herein, high-entropy oxide (FeCoNiCrCuO) electrocatalysts featuring grain-like structure and oxygen vacancies-enriched surface were synthesized through an ultra-fast non-equilibrium high-temperature shock. The introduction of oxygen vacancies modulates the electronic structure and increases the carrier concentration, accelerating the rate-determining step of the oxygen evolution reactions and reducing the overpotential of oxygen evolution reactions. Consequently, the synthesized FeCoNiCrCuO electrocatalyst delivers a low overpotential of 256 mV at a current density of 10 mA·cm⁻² and a Tafel slope of 48.2 mV·dec⁻¹ in 1 M KOH, which is superior to samples lacking oxygen vacancies after annealing. This study presents an alternative approach to enhancing OER activity by employing a high-entropy oxide engineering strategy.</div></div>","PeriodicalId":100892,"journal":{"name":"Materials Today Catalysis","volume":"8 ","pages":"Article 100086"},"PeriodicalIF":0.0,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-27DOI: 10.1016/j.mtcata.2024.100085
Evgenia Kountoupi , Diana Piankova , Mikhail Agrachev , Zixuan Chen , Alberto Garbujo , Paula M. Abdala , Christoph R. Müller , Alexey Fedorov
<div><div>Harnessing two-dimensional (2D) materials for catalytic applications is promising due to the high site utilization. Here, we synthesized a 2D molybdenum carbonitride of the MXene family, Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub>, and applied it as a catalyst for ammonia synthesis and decomposition, the essential reactions to establish NH<sub>3</sub> as an energy vector. We determine the thermal stability limit of Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> under H<sub>2</sub> flow to be ca. 575 °C. Exceeding this temperature results, under H<sub>2</sub>, in a transformation of the predominantly defunctionalized Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> to a 3D Mo<sub>2</sub>(C,N) phase, which prevents the complete defunctionalization of Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> while retaining its 2D morphology. Before this phase transformation occurs, the remaining <em>T</em><sub><em>x</em></sub> species reside in the interior layers of the mostly defunctionalized Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> nanoplatelets, with the amorphous exterior being free from <em>T</em><sub><em>x</em></sub> groups, rendering the Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> nanoplatelets chemically anisotropic in the direction orthogonal to the basal plane. The effect of this structure on catalytic properties is highlighted in the thermocatalytic synthesis and decomposition of NH<sub>3</sub>. In the latter reaction, Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> shows similar gravimetric rates to a reference bulk β-Μο<sub>2</sub>Ν catalyst, which is ascribed to the presence of too narrow 2D pores (ca. 5.2 Å) with irregular shapes due to a disorder in the stacking of nanosheets in Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub>, limiting interlayer diffusion. A deactivation pathway in Mo-based MXenes was identified, and it relates to a precipitation of carbon vacancies to metallic molybdenum under NH<sub>3</sub> decomposition conditions. While the ammonia decomposition reaction shows no dependence of the reaction rate on the specific H<sub>2</sub> pretreatment of Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> (500 or 575 °C), the gravimetric ammonia formation rate increases appreciably with H<sub>2</sub> pretreatment, <em>viz</em>., Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> pretreated at 575 °C outperforms by ca. four times both the reference β-Μο<sub>2</sub>Ν catalyst and Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> pretreated at 500 °C, explained by a smaller molecule size of the reactants H<sub>2</sub> and N<sub>2</sub> relative to NH<sub>3</sub>, and an increased accessibility and utilization of the interlayer space for ammonia synthesis. Overall, our study highlights the importance of addressing limitations due to small pore sizes in multilayered MXenes and the stability of carbon vacancies while simultaneously using optimized pretreatment conditions for surface defunctio
{"title":"Multilayered molybdenum carbonitride MXene: Reductive defunctionalization, thermal stability, and catalysis of ammonia synthesis and decomposition","authors":"Evgenia Kountoupi , Diana Piankova , Mikhail Agrachev , Zixuan Chen , Alberto Garbujo , Paula M. Abdala , Christoph R. Müller , Alexey Fedorov","doi":"10.1016/j.mtcata.2024.100085","DOIUrl":"10.1016/j.mtcata.2024.100085","url":null,"abstract":"<div><div>Harnessing two-dimensional (2D) materials for catalytic applications is promising due to the high site utilization. Here, we synthesized a 2D molybdenum carbonitride of the MXene family, Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub>, and applied it as a catalyst for ammonia synthesis and decomposition, the essential reactions to establish NH<sub>3</sub> as an energy vector. We determine the thermal stability limit of Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> under H<sub>2</sub> flow to be ca. 575 °C. Exceeding this temperature results, under H<sub>2</sub>, in a transformation of the predominantly defunctionalized Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> to a 3D Mo<sub>2</sub>(C,N) phase, which prevents the complete defunctionalization of Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> while retaining its 2D morphology. Before this phase transformation occurs, the remaining <em>T</em><sub><em>x</em></sub> species reside in the interior layers of the mostly defunctionalized Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> nanoplatelets, with the amorphous exterior being free from <em>T</em><sub><em>x</em></sub> groups, rendering the Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> nanoplatelets chemically anisotropic in the direction orthogonal to the basal plane. The effect of this structure on catalytic properties is highlighted in the thermocatalytic synthesis and decomposition of NH<sub>3</sub>. In the latter reaction, Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> shows similar gravimetric rates to a reference bulk β-Μο<sub>2</sub>Ν catalyst, which is ascribed to the presence of too narrow 2D pores (ca. 5.2 Å) with irregular shapes due to a disorder in the stacking of nanosheets in Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub>, limiting interlayer diffusion. A deactivation pathway in Mo-based MXenes was identified, and it relates to a precipitation of carbon vacancies to metallic molybdenum under NH<sub>3</sub> decomposition conditions. While the ammonia decomposition reaction shows no dependence of the reaction rate on the specific H<sub>2</sub> pretreatment of Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> (500 or 575 °C), the gravimetric ammonia formation rate increases appreciably with H<sub>2</sub> pretreatment, <em>viz</em>., Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> pretreated at 575 °C outperforms by ca. four times both the reference β-Μο<sub>2</sub>Ν catalyst and Mo<sub>2</sub>(C,N)<em>T</em><sub><em>x</em></sub> pretreated at 500 °C, explained by a smaller molecule size of the reactants H<sub>2</sub> and N<sub>2</sub> relative to NH<sub>3</sub>, and an increased accessibility and utilization of the interlayer space for ammonia synthesis. Overall, our study highlights the importance of addressing limitations due to small pore sizes in multilayered MXenes and the stability of carbon vacancies while simultaneously using optimized pretreatment conditions for surface defunctio","PeriodicalId":100892,"journal":{"name":"Materials Today Catalysis","volume":"8 ","pages":"Article 100085"},"PeriodicalIF":0.0,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-25DOI: 10.1016/j.mtcata.2024.100087
Huamei Li , Mengyuan Li , Lingling Liao , Han Yang , Kun Xiang , Guoqiang Luo , Mingjiang Xie
The challenge of the complex oxygen evolution reaction (OER) currently impedes the efficient production of hydrogen via electrolytic water splitting. To address this issue, the development and improvement of effective electrocatalysts are required. LiCoO2, a key material in lithium-ion batteries, has shown promising potential as an electrocatalyst for electrochemical energy conversion. However, OER catalysts derived from LiCoO2 have faced obstacles such as high overpotential and a complicated preparation process. In this study, the preparation method is adjusted to optimize the synthesis of Li1-xCoO2 with a defective structure, resulting in an impressive overpotential of only 290 mV at a current density of 100 mA cm−2 and a remarkable Tafel slope of 15.2 mV dec−1. The exceptional catalytic activity of Li1-xCoO2 can be attributed to the absence of Li, which triggers oxidative alterations in the electronic structure of Co. Density functional theory (DFT) calculations reveal that Li defects can influence the d-band center of active Co sites, enhancing the adsorption capabilities of Co sites towards *OOH intermediates and increasing the conductivity of the electrocatalyst during the OER process. These alterations improve the velocity of the crucial step in the reaction, ultimately boosting the catalyst's overall performance and efficiency.
{"title":"Boosting oxygen evolution of LiCoO2 electrocatalysts via lithium defect","authors":"Huamei Li , Mengyuan Li , Lingling Liao , Han Yang , Kun Xiang , Guoqiang Luo , Mingjiang Xie","doi":"10.1016/j.mtcata.2024.100087","DOIUrl":"10.1016/j.mtcata.2024.100087","url":null,"abstract":"<div><div>The challenge of the complex oxygen evolution reaction (OER) currently impedes the efficient production of hydrogen via electrolytic water splitting. To address this issue, the development and improvement of effective electrocatalysts are required. LiCoO<sub>2</sub>, a key material in lithium-ion batteries, has shown promising potential as an electrocatalyst for electrochemical energy conversion. However, OER catalysts derived from LiCoO<sub>2</sub> have faced obstacles such as high overpotential and a complicated preparation process. In this study, the preparation method is adjusted to optimize the synthesis of Li<sub>1-x</sub>CoO<sub>2</sub> with a defective structure, resulting in an impressive overpotential of only 290 mV at a current density of 100 mA cm<sup>−2</sup> and a remarkable Tafel slope of 15.2 mV dec<sup>−1</sup>. The exceptional catalytic activity of Li<sub>1-x</sub>CoO<sub>2</sub> can be attributed to the absence of Li, which triggers oxidative alterations in the electronic structure of Co. Density functional theory (DFT) calculations reveal that Li defects can influence the d-band center of active Co sites, enhancing the adsorption capabilities of Co sites towards *OOH intermediates and increasing the conductivity of the electrocatalyst during the OER process. These alterations improve the velocity of the crucial step in the reaction, ultimately boosting the catalyst's overall performance and efficiency.</div></div>","PeriodicalId":100892,"journal":{"name":"Materials Today Catalysis","volume":"8 ","pages":"Article 100087"},"PeriodicalIF":0.0,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-10DOI: 10.1016/j.mtcata.2024.100081
Jian Chen , Yixin Huang , Liu Wan, Cheng Du, Yan Zhang, Mingjiang Xie
The development of CdS-based photocatalysts with the appropriate bandgap structure, impressive optical response, and long-lasting reusability is both crucial and challenging. The heterogeneous catalyst, made up of polytriazine and CdS, demonstrates exceptional photogenerated charge separation and transfer capabilities, as well as superior CO2 adsorption abilities. In this study, we have shown that the CO2 photoassisted reduction efficiency of CdS nanosheets can be significantly improved through surface modification with a polytriazine polymer coating. The PP@CdS photocatalyst has been thoroughly characterized using techniques such as XRD, TEM, SEM, N2 adsorption-desorption, CO2 adsorption, DRS, XPS, and photoelectric performance tests. The catalytic performance of the PP@CdS was assessed through photoassisted CO2 reduction reactions under visible light irradiation in an aqueous medium at 25 ℃. Owing to its enhanced CO2 adsorption capacity and the efficient separation and utilization of photogenerated electrons, the PP@CdS photocatalyst demonstrated a CO yield (6.7 μmol/g/h) 1.3 times greater and a CH4 yield (4.2 μmol/g/h) 1.3 times higher than that of bare CdS nanosheets. Furthermore, the PP@CdS photocatalyst demonstrated outstanding reusability in CO2 reduction reactions. This study presents a novel approach to enhancing the CO2 adsorption capacity and modulating the bandgap structure of polymer-coated semiconductor materials.
{"title":"Polytriazine@CdS nanosheets as photosensitizer free catalyst for efficient photocatalytic reduction of CO2","authors":"Jian Chen , Yixin Huang , Liu Wan, Cheng Du, Yan Zhang, Mingjiang Xie","doi":"10.1016/j.mtcata.2024.100081","DOIUrl":"10.1016/j.mtcata.2024.100081","url":null,"abstract":"<div><div>The development of CdS-based photocatalysts with the appropriate bandgap structure, impressive optical response, and long-lasting reusability is both crucial and challenging. The heterogeneous catalyst, made up of polytriazine and CdS, demonstrates exceptional photogenerated charge separation and transfer capabilities, as well as superior CO<sub>2</sub> adsorption abilities. In this study, we have shown that the CO<sub>2</sub> photoassisted reduction efficiency of CdS nanosheets can be significantly improved through surface modification with a polytriazine polymer coating. The PP@CdS photocatalyst has been thoroughly characterized using techniques such as XRD, TEM, SEM, N<sub>2</sub> adsorption-desorption, CO<sub>2</sub> adsorption, DRS, XPS, and photoelectric performance tests. The catalytic performance of the PP@CdS was assessed through photoassisted CO<sub>2</sub> reduction reactions under visible light irradiation in an aqueous medium at 25 ℃. Owing to its enhanced CO<sub>2</sub> adsorption capacity and the efficient separation and utilization of photogenerated electrons, the PP@CdS photocatalyst demonstrated a CO yield (6.7 μmol/g/h) 1.3 times greater and a CH<sub>4</sub> yield (4.2 μmol/g/h) 1.3 times higher than that of bare CdS nanosheets. Furthermore, the PP@CdS photocatalyst demonstrated outstanding reusability in CO<sub>2</sub> reduction reactions. This study presents a novel approach to enhancing the CO<sub>2</sub> adsorption capacity and modulating the bandgap structure of polymer-coated semiconductor materials.</div></div>","PeriodicalId":100892,"journal":{"name":"Materials Today Catalysis","volume":"8 ","pages":"Article 100081"},"PeriodicalIF":0.0,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-01DOI: 10.1016/j.mtcata.2024.100079
Meiling Liu , Cuili Xiang , Yongjin Zou , Fen Xu , Lixian Sun , Ningbo Qin
The performance of single-component hydrogen evolution reaction (HER) electrocatalysts in terms of physicochemical properties and electrocatalytic efficiency has shown limitations for large-scale industrial applications. Consequently, developing new HER electrocatalysts with superior performance and mature technology is crucial for advancing this field. In this study, nickel foam/reduced graphene oxide/CoNi2S4-MoO2 (NF/rGO/CoNi2S4-MoO2) was prepared using a combination of water bath and two-step hydrothermal methods. Reduced graphene oxide (rGO) enhances the catalyst’s conductivity and induces uniform distribution of CoNi2S4. The sheet-like CoNi2S4 provides numerous active sites for the vertically distributed MoO2 nanosheets, reducing agglomeration and ensuring even distribution on the surface. The synergistic effect among rGO, CoNi2S4, and MoO2, along with their unique structures, facilitates charge transfer, enhancing the material’s electrochemical hydrogen evolution capabilities even more. The synthesized NF/rGO/CoNi2S4-MoO2 nanosheets exhibited excellent electrocatalytic performance. The overpotential of NF/rGO/CoNi2S4-MoO2 was as low as 65 mV in a 1.0 M KOH solution at a current density of 10 mA·cm−2, and the Tafel slope was 96.48 mV·dec−1.
{"title":"Nickel foam/reduced graphene oxide/CoNi2S4-MoO2 nanosheets with a core–shell structure formed: An efficient electrocatalyst for the hydrogen evolution reaction","authors":"Meiling Liu , Cuili Xiang , Yongjin Zou , Fen Xu , Lixian Sun , Ningbo Qin","doi":"10.1016/j.mtcata.2024.100079","DOIUrl":"10.1016/j.mtcata.2024.100079","url":null,"abstract":"<div><div>The performance of single-component hydrogen evolution reaction (HER) electrocatalysts in terms of physicochemical properties and electrocatalytic efficiency has shown limitations for large-scale industrial applications. Consequently, developing new HER electrocatalysts with superior performance and mature technology is crucial for advancing this field. In this study, nickel foam/reduced graphene oxide/CoNi<sub>2</sub>S<sub>4</sub>-MoO<sub>2</sub> (NF/rGO/CoNi<sub>2</sub>S<sub>4</sub>-MoO<sub>2</sub>) was prepared using a combination of water bath and two-step hydrothermal methods. Reduced graphene oxide (rGO) enhances the catalyst’s conductivity and induces uniform distribution of CoNi<sub>2</sub>S<sub>4</sub>. The sheet-like CoNi<sub>2</sub>S<sub>4</sub> provides numerous active sites for the vertically distributed MoO<sub>2</sub> nanosheets, reducing agglomeration and ensuring even distribution on the surface. The synergistic effect among rGO, CoNi<sub>2</sub>S<sub>4</sub>, and MoO<sub>2</sub>, along with their unique structures, facilitates charge transfer, enhancing the material’s electrochemical hydrogen evolution capabilities even more. The synthesized NF/rGO/CoNi<sub>2</sub>S<sub>4</sub>-MoO<sub>2</sub> nanosheets exhibited excellent electrocatalytic performance. The overpotential of NF/rGO/CoNi<sub>2</sub>S<sub>4</sub>-MoO<sub>2</sub> was as low as 65 mV in a 1.0 M KOH solution at a current density of 10 mA·cm<sup>−2</sup>, and the Tafel slope was 96.48 mV·dec<sup>−1</sup>.</div></div>","PeriodicalId":100892,"journal":{"name":"Materials Today Catalysis","volume":"7 ","pages":"Article 100079"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-01DOI: 10.1016/j.mtcata.2024.100076
Ángel Morales-García , José D. Gouveia , Anna Vidal López , Aleix Comas-Vives , Francesc Viñes , José R.B. Gomes , Francesc Illas
Pristine Mo2C MXene has been recently highlighted as a highly active and robust catalyst for the reverse water gas shift (RWGS) reaction. Here, first-principles calculations based on density functional theory (DFT) coupled with mean-field microkinetic (MKM) simulations are performed to investigate the effects of the atomic layer stacking and the surface functionalization with oxo groups on the catalyst performance. The calculated data show that ABA stacked MXene has a reactivity higher than the corresponding ABC counterpart. Moreover, a 2/3 surface monolayer oxygen coverage on both stackings (i.e., Mo2CO4/3 MXene) enhances the overall reactivity compared with their pristine Mo2C counterparts. The reactivity enhancement is small for the more stable ABA-stacked model, with a CO gas production aligned with experimental reports. However, the partial O-surface termination in the MXene with ABC stacking offers a more enhanced reactivity, supported by the higher CO gas production for the Mo2C MXene models here considered. Thus, the MXene stacking and its functionalization are key aspects affecting the performance of the Mo2C MXene for the RGWS reaction, which must be considered for realistic catalytic applications of MXenes.
{"title":"MXene termination and stacking bias on the reverse water gas shift reaction catalysis","authors":"Ángel Morales-García , José D. Gouveia , Anna Vidal López , Aleix Comas-Vives , Francesc Viñes , José R.B. Gomes , Francesc Illas","doi":"10.1016/j.mtcata.2024.100076","DOIUrl":"10.1016/j.mtcata.2024.100076","url":null,"abstract":"<div><div>Pristine Mo<sub>2</sub>C MXene has been recently highlighted as a highly active and robust catalyst for the reverse water gas shift (RWGS) reaction. Here, first-principles calculations based on density functional theory (DFT) coupled with mean-field microkinetic (MKM) simulations are performed to investigate the effects of the atomic layer stacking and the surface functionalization with oxo groups on the catalyst performance. The calculated data show that ABA stacked MXene has a reactivity higher than the corresponding ABC counterpart. Moreover, a <sup>2</sup>/<sub>3</sub> surface monolayer oxygen coverage on both stackings (<em>i.e.</em>, Mo<sub>2</sub>CO<sub>4/3</sub> MXene) enhances the overall reactivity compared with their pristine Mo<sub>2</sub>C counterparts. The reactivity enhancement is small for the more stable ABA-stacked model, with a CO gas production aligned with experimental reports. However, the partial O-surface termination in the MXene with ABC stacking offers a more enhanced reactivity, supported by the higher CO gas production for the Mo<sub>2</sub>C MXene models here considered. Thus, the MXene stacking and its functionalization are key aspects affecting the performance of the Mo<sub>2</sub>C MXene for the RGWS reaction, which must be considered for realistic catalytic applications of MXenes.</div></div>","PeriodicalId":100892,"journal":{"name":"Materials Today Catalysis","volume":"7 ","pages":"Article 100076"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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