Fabrication of nitrogen-doped BiVO4/CrFe2O4@CNTs heterojunction for enhanced photocatalytic degradation of pesticides

Abstract

Photocatalysis, a green technology for environmental protection, is gaining attention due to its energy efficiency and sustainability. However, the recombination of photogenerated electron-hole pairs is very fast, which decreases quantum efficiency. Recent advances suggest that the fabrication of heterojunction-based materials can address these limitations. In the present work, Nitrogen-doped BiVO₄ (NBVO), CrFe₂O₄ (CF), and CNTs-based nanocomposite (NBVO/CF@CNTs) were fabricated via a simple co-precipitation and ultrasonication method. The fabricated samples were characterized using different physicochemical techniques. X-rays Diffraction (XRD) confirms the monoclinic and spinel crystal structure for NBVO and CF respectively. Scanning Electron Microscopy (SEM) confirms the entanglement of carbon nanotubes with nanoparticles of NBVO/CF. Optical analysis reveals the decrease in bandgap energy after composite formation which greatly enhances the photocatalytic efficiency of NBVO/CF@CNTs. The photoluminescence (PL) analysis confirmed that NBVO/CF@CNTs have lowest recombination rate among all prepared photocatalysts. The synthesized photocatalysts were employed in the photodegradation of chlorpyrifos (CP) and Triazophos (TA). The degradation efficiency of the NBVO/CF@CNTs was highest (88 % CP and 85 % TA) as compared to the NBVO, CF, and NBVO/CF. The excellent photocatalytic properties of NBVO/CF@CNTs were attributed to the increase in active sites, reduction in bandgap energy and enhanced separation rate of photogenerated species. The NBVO/CF@CNTs proved to be an efficient and stable photocatalyst for wastewater remediation.