UV/visible light active CuCrO2 nanoparticle–SnO2 nanofiber p–n heterostructured photocatalysts for photocatalytic applications

Abstract

CuCrO₂ nanoparticle decorated SnO₂ nanofiber composites have been prepared as novel p–n heterostructured semiconductor photocatalysts for the degradation of organic pollutants in wastewater. The composite structure was achieved via drop casting of various amounts of hydrothermally derived CuCrO₂ nanoparticles on electrospun SnO₂ nanofibers. The microstructural and morphological features of each semiconductor and the formation of p–n heterojunctions between them were characterized. In addition, the photo-response and electrochemical properties of the samples were determined. The photocatalytic activity of the heterostructured photocatalysts was investigated systematically as a function of the amount of CuCrO₂ nanoparticles in the samples. Experimental results showed that the optimal decoration amount was 0.6 wt% CuCrO₂ on SnO₂. This composite photocatalyst displayed a 41% higher rate constant value compared to pure SnO₂ nanofibers in the degradation of methylene blue dye molecules and reached 83% degradation under UV/visible light irradiation after 1 h. The increase in the photocatalytic activity was ascribed to the incorporation of Cr³⁺ and Cu⁺ cations into the SnO₂ host lattice and the more effective electron–hole pair separation in the heterostructured sample. The presented data here are highly convincing in comparison to those of UV active p–n heterostructured photocatalysts reported previously in the literature. Therefore, this work opens the way to develop visible light active p–n heterostructured semiconductor photocatalysts using p-type delafossites with n-type oxides.