Conversion of Catalytically Inert 2D Bismuth Oxide Nanosheets for Effective Electrochemical Hydrogen Evolution Reaction Catalysis Via Oxygen Vacancy Concentration Modulation
Overview
Authors
Affiliations
Oxygen vacancies (V) in electrocatalysts are closely correlated with the hydrogen evolution reaction (HER) activity. The role of vacancy defects and the effect of their concentration, however, yet remains unclear. Herein, BiO, an unfavorable electrocatalyst for the HER due to a less than ideal hydrogen adsorption Gibbs free energy (ΔG), is utilized as a perfect model to explore the function of V on HER performance. Through a facile plasma irradiation strategy, BiO nanosheets with different V concentrations are fabricated to evaluate the influence of defects on the HER process. Unexpectedly, while the generated oxygen vacancies contribute to the enhanced HER performance, higher V concentrations beyond a saturation value result in a significant drop in HER activity. By tunning the V concentration in the BiO nanosheets via adjusting the treatment time, the BiO catalyst with an optimized oxygen vacancy concentration and detectable charge carrier concentration of 1.52 × 10 cm demonstrates enhanced HER performance with an overpotential of 174.2 mV to reach 10 mA cm, a Tafel slope of 80 mV dec, and an exchange current density of 316 mA cm in an alkaline solution, which approaches the top-tier activity among Bi-based HER electrocatalysts. Density-functional theory calculations confirm the preferred adsorption of H* onto BiO as a function of oxygen chemical potential (∆μ) and oxygen partial potential (P) and reveal that high V concentrations result in excessive stability of adsorbed hydrogen and hence the inferior HER activity. This study reveals the oxygen vacancy concentration-HER catalytic activity relationship and provides insights into activating catalytically inert materials into highly efficient electrocatalysts.
Liu S, Zhang Z, Dastafkan K, Shen Y, Zhao C, Wang M Nat Commun. 2025; 16(1):773.
PMID: 39824853 PMC: 11742019. DOI: 10.1038/s41467-025-55856-4.
In Situ Reconstructing NiFe Oxalate Toward Overall Water Splitting.
Zhang Z, Ren X, Dai W, Zhang H, Sun Z, Ye Z Adv Sci (Weinh). 2024; 11(44):e2408754.
PMID: 39360598 PMC: 11600197. DOI: 10.1002/advs.202408754.
Zang B, Liu X, Gu C, Chen J, Wang L, Zheng W Nanomaterials (Basel). 2024; 14(14).
PMID: 39057849 PMC: 11280403. DOI: 10.3390/nano14141172.
Jin J, Wang X, Hu Y, Zhang Z, Liu H, Yin J Nanomicro Lett. 2024; 16(1):63.
PMID: 38168843 PMC: 10761665. DOI: 10.1007/s40820-023-01291-3.
Machine Learning-Assisted Low-Dimensional Electrocatalysts Design for Hydrogen Evolution Reaction.
Li J, Wu N, Zhang J, Wu H, Pan K, Wang Y Nanomicro Lett. 2023; 15(1):227.
PMID: 37831203 PMC: 10575847. DOI: 10.1007/s40820-023-01192-5.