Modified Ta2O5-x prepared by NaBH4 reduction for enhance its photocatalytic activity

Abstract

The generation of oxygen vacancies assumes a pivotal role in the photocatalytic degradation of antibiotics. Surface oxygen vacancies serve as deterrents to the recombination of photogenerated carriers, thereby augmenting photocatalytic efficiency. In this work, the NaBH4 reduction technique was adopted to introduce oxygen vacancies onto the surface of Ta2O5-x, thus enhancing its photocatalytic powers. Remarkably, the photocatalytic activity of the modified Ta2O5-x-0.5 M samples exhibited significant improvement upon treatment with NaBH4 solution at varied concentrations. Characterization of the modified Ta2O5-x samples was conducted using a suite of techniques including XRD, FT-IR, UV–vis DRS, ESR, XPS, and EPR. Notably, the EPR spectrum provided compelling evidence of the presence of oxygen vacancies, affirming their existence on the surface of the modified Ta2O5-x samples. To further corroborate the formation of oxygen vacancies, tetracycline (TC) solution was employed as a simulated pollutant, revealing a marked enhancement in visible light catalytic activity through experimental observations. The findings elucidate that the defect sites engendered by oxygen vacancies primarily enhance the efficiency of electron-hole pair separation and facilitate greater absorption of visible light, thereby amplifying photocatalytic activity. The modification of Ta2O5-x samples by NaBH4 reduction predominantly facilitates the introduction of oxygen vacancies on the surface, consequently bolstering photocatalytic performance. This exemplifies a noteworthy approach for significantly enhancing the photocatalytic activity of Ta2O5-x, providing valuable insights for future design strategies.