One of the main scientific and technological challenges in the application of nanostructured semiconductors as photocatalysts is related to the fact that materials which present better performances are activated by radiation in the UV region of the electromagnetic spectrum. However, materials that can be activated by radiation in the visible region (lower band gap value - Ebg) and therefore take more efficiently the sunlight, have as disadvantage the lower photogenerated charges lifetime, resulting in lower efficiencies when compared to the oxides commonly used. One of the promising alternatives of great scientific and technological interest to overcome this challenge lies in developing heterostructures containing semiconductor with Ebg value in the visible region. Therefore, the formation of heterostructured films containing both BiVO4 ( Ebg = 2.4 eV ) would be an alternative to obtain an enhanced process efficiency, and facilitate the material recycling. So to meet with these challenges, we have proposed in this project the preparation of BiVO4/Bi2O3 e BiVO4/V2O5 thin films and the study of their photoactivity in organic pollutants degradation under visible light. The heterostructured films will be prepared by PBM (purpose-built materials) strategy using BiVO4 precursors solution over oxide semiconductor (Bi2O3, V2O5) films previously deposited. Structural and morphological characterizations will be studied using XRD, Raman spectroscopy, photoluminescence, X-ray absorption and electron microscopy techniques. Electrical measurements, as capacitance and photocurrent, will be conducted to better understand the organic pollutants photodegradation mechanism.
News published in Agência FAPESP Newsletter about the scholarship: