Integrating plasmonic effect and nano-heterojunction formation for boosted light harvesting and photocatalytic performance using CaWO4/Ag2MoO4 and its antibacterial applications

摘要

In the present work, CaWO4/Ag2MoO4 nanohybrid was synthesized by sono-chemical method. Fourier-transform infrared spectroscopy (FTIR), UV-visible diffuse reflectance spectroscopy (UV-vis DRS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDAX) and BET surface area analyzer were used to characterize the structure and optical properties of CaWO4/Ag2MoO4 nanohybrid. The HRTEM image represents the formation of CaWO4/ Ag2MoO4 nanohybrid with clear facets and narrow size range. The XRD results showed that CaWO4/Ag2MoO4 nanohybrid composed of combined phases of CaWO4 and Ag2MoO4. A red-shift was observed in the optical absorption of nanohybrid after loading Ag2MoO4 on CaWO4. The photodegradation of MB by CaWO4/Ag2MoO4 nanohybrid (91.4%) showed excellent performance when compared with the pure Ag2MoO4 (59.6%) and CaWO4 (14.3%) under visible light. The scavenging test revealed that the key species responsible for the degradation of MB dye was hydroxide radical ((OH)-O-center dot). The degradation of MB was well fitted to the pseudo-first-order kinetics with a high regression coefficient value (R-2 > 0.95). The photostability and reusability of the nanohybrid was studied and the nanohybrid showed almost same degradation efficiency even at 6th cycle. The nanohybrid showed enhanced antimicrobial activity against Escherichia coli and Bacillus subtilis. Therefore, CaWO4/Ag2MoO4 nanohybrid photocatalyst can be used as an effective candidate for environmental remediation through photocatalysis and bactericidal applications.