Enhanced Hydrogen Evolution Using $β$-MnO$_2$ Monolayer on Ni Electrode with Engineered Oxygen Vacancies
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| Autori principali: | , , , |
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| Natura: | Preprint |
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2025
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| _version_ | 1866916652615991296 |
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| author | Rahman, Faysal Mamun, Abdul Ahad Hussain, Auronno Ovid Talukder, Muhammad Anisuzzaman |
| author_facet | Rahman, Faysal Mamun, Abdul Ahad Hussain, Auronno Ovid Talukder, Muhammad Anisuzzaman |
| contents | Developing cost-effective and high-performance electrodes is critical for advancing hydrogen (H$_2$) production through electrochemical water splitting. In this study, we present a novel electrode design by depositing a $β$-MnO$_2$ monolayer on a conventional Ni(100) substrate (MnO$_2$(110)/Ni(100)) and systematically investigate its electrocatalytic properties. This work uniquely explores the influence of oxygen vacancies (OVs) at distinct sites -- Osub-top and bridge sites -- on both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Our findings reveal that the Osub-top vacancy (OOV-MnO$_2$(110)/Ni(100)) significantly enhances HER activity, achieving a hydrogen Gibbs free energy ($ΔG_{\rm H}$) of $-0.015$ eV, which surpasses the performance of noble metals such as Pt/C ($-0.082$ eV) and Ir ($-0.08$ eV). Additionally, the cathodic exchange current density $(J_{0,c})$ of OOV-MnO$_2$(110)/Ni(100) reaches $10^{-0.774}$ Acm$^{-2}$, outperforming Pt/C ($10^{-0.92}$ Acm$^{-2}$) and Ir ($10^{-1.44}$ Acm$^{-2}$). Electrochemical analysis confirms a cathodic activation overpotential $(η_{a,c})$ of 0.141 V at 10 mAcm$^{-2}$ in a 0.5 M H$_2$SO$_4$ solution, achieving a hydrogen production rate (HPR) of 0.91 mmolh$^{-1}$cm$^{-2}$ at an applied voltage ($V_{\rm app}$) of 1.60 V. This study provides the first comprehensive analysis of site-specific oxygen vacancy effects on bifunctional MnO$_2$-based electrodes, demonstrating superior HER activity while maintaining dual functionality for both cathodic and anodic processes. Our results highlight the potential of engineered oxygen vacancies to develop low-cost, high-efficiency electrodes for sustainable hydrogen production, offering a competitive alternative to precious metal-based catalysts. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2503_11234 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Enhanced Hydrogen Evolution Using $β$-MnO$_2$ Monolayer on Ni Electrode with Engineered Oxygen Vacancies Rahman, Faysal Mamun, Abdul Ahad Hussain, Auronno Ovid Talukder, Muhammad Anisuzzaman Chemical Physics Materials Science Developing cost-effective and high-performance electrodes is critical for advancing hydrogen (H$_2$) production through electrochemical water splitting. In this study, we present a novel electrode design by depositing a $β$-MnO$_2$ monolayer on a conventional Ni(100) substrate (MnO$_2$(110)/Ni(100)) and systematically investigate its electrocatalytic properties. This work uniquely explores the influence of oxygen vacancies (OVs) at distinct sites -- Osub-top and bridge sites -- on both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Our findings reveal that the Osub-top vacancy (OOV-MnO$_2$(110)/Ni(100)) significantly enhances HER activity, achieving a hydrogen Gibbs free energy ($ΔG_{\rm H}$) of $-0.015$ eV, which surpasses the performance of noble metals such as Pt/C ($-0.082$ eV) and Ir ($-0.08$ eV). Additionally, the cathodic exchange current density $(J_{0,c})$ of OOV-MnO$_2$(110)/Ni(100) reaches $10^{-0.774}$ Acm$^{-2}$, outperforming Pt/C ($10^{-0.92}$ Acm$^{-2}$) and Ir ($10^{-1.44}$ Acm$^{-2}$). Electrochemical analysis confirms a cathodic activation overpotential $(η_{a,c})$ of 0.141 V at 10 mAcm$^{-2}$ in a 0.5 M H$_2$SO$_4$ solution, achieving a hydrogen production rate (HPR) of 0.91 mmolh$^{-1}$cm$^{-2}$ at an applied voltage ($V_{\rm app}$) of 1.60 V. This study provides the first comprehensive analysis of site-specific oxygen vacancy effects on bifunctional MnO$_2$-based electrodes, demonstrating superior HER activity while maintaining dual functionality for both cathodic and anodic processes. Our results highlight the potential of engineered oxygen vacancies to develop low-cost, high-efficiency electrodes for sustainable hydrogen production, offering a competitive alternative to precious metal-based catalysts. |
| title | Enhanced Hydrogen Evolution Using $β$-MnO$_2$ Monolayer on Ni Electrode with Engineered Oxygen Vacancies |
| topic | Chemical Physics Materials Science |
| url | https://arxiv.org/abs/2503.11234 |