Base-induced phase and morphology evolution of Ta2O5 to Ta-based compound nanostructures: synthesis and characterization

초록

This study investigates the synthesis and characterization of Ta-based compound nanostructures modified from tantalum pentoxide (Ta2O5) using base-assisted hydrothermal treatments with NaOH, KOH, and Sr(OH)2. The morphologies, crystal structures, surface chemistry, optical properties, and electrochemical performance of the resulting materials were analyzed in depth. The KOH treatment produced octahedral KTa2O5(OH).nH2O nanostructures, NaOH yielded cubic NaTaO3, and Sr(OH)2 resulted in rod-like Ta2O5 with SrTa2O6 as secondary phase. The KOH-treated sample exhibited superior hydrophilicity and electrochemical performance for the oxygen evolution reaction (OER) compared to the other samples. This was attributed to the presence of hydroxyl groups, incorporation of K+ ions, and improved OH- adsorption. A growth mechanism and structure-property relationships of the base-modified materials were also provided. The results of this study demonstrate how base-assisted treatments can be used to engineer the morphology, structure, and properties of Ta-based compound nanostructures for various applications in catalysis and renewable energy.

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