Hydrogen-bonded interfacial hydroxyls enable efficient s-scheme charge transfer in crystalline Ta2O5@amorphous TaOx homojunction for superior photocatalysis

The construction of amorphous/crystalline homojunctions with strong interfacial interaction represents a pivotal strategy for advancing photocatalytic performance. Herein, we report a novel crystalline Ta2O5@amorphous TaOx core-shell homojunction, engineered with hydrogen-bonded interfacial hydroxyl...

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Bibliographic Details
Published in:Journal of alloys and compounds Vol. 1047; p. 185105
Main Authors: Wang, Yan, Liu, Chang, Fu, Rong, Wang, Chao, Shi, Yuqi, Zhang, Yuelan
Format: Journal Article
Language:English
Published: Elsevier B.V 05.12.2025
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ISSN:0925-8388
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Summary:The construction of amorphous/crystalline homojunctions with strong interfacial interaction represents a pivotal strategy for advancing photocatalytic performance. Herein, we report a novel crystalline Ta2O5@amorphous TaOx core-shell homojunction, engineered with hydrogen-bonded interfacial hydroxyls (Ta-O⋅⋅⋅H-O-Ta). Among all prepared samples, A/C-TO200 (containing 24.9 % bridging-OH groups) exhibits the highest H2-evolving activity at a rate of 1.83 mmol·g−1·h−1, nearly 10 times faster than Crystalline (core)-Ta2O5. The enhanced catalytic activity is primarily attributed to the synergistic effect between the built-in electric field and hydrogen-bonded interfacial hydroxyl groups, which collectively creates a robust driving force for charge separation. Experimental validation confirms the S-scheme charge transfer mechanism, while density functional theory (DFT) calculations further elucidate this mechanism. Notably, the calculations reveal that the crystalline Ta2O5@amorphous TaOx homojunction significantly reduces the hydrogen adsorption free energy (ΔGH*), thereby facilitating rapid H2 desorption and ultimately leading to superior catalytic performance. This work establishes a generalizable strategy for designing high-performance homojunctions by exploiting hydrogen-bonded interfacial groups, offering a new paradigm for enhancing photocatalytic activity in inorganic semiconductors. [Display omitted] •Crystalline Ta2O5@amorphous TaOx core-shell homojunction was prepared.•A/C-TO200 exhibited high efficiency and stability of hydrogen evolution.•Hydrogen-bonded interfacial hydroxyls boosted charge migration.•Built-in electric field enhanced the carrier separation.•The S-scheme charge transfer mechanism was demonstrated.
ISSN:0925-8388
DOI:10.1016/j.jallcom.2025.185105