Ultraviolet light induced dye degradation of methylene blue in the presence of photocatalytic CdSe and ZnSe nanoparticles

Abstract

• Nanoparticles of cadmium selenide (CdSe) and zinc selenide (ZnSe) have been synthesized by chemical co-precipitation and hydrothermal route using mercaptoethanol and hydrazine hydrate as a capping agent and reducing agent. • As synthesized ZnSe nanoparticles shows higher methylene blue (MB) dye degradation under UV light irradiation compared to CdSe nanoparticles. • The kinetic study of the degradation process with both the samples (CdSe and ZnSe) showed to obey pseudo-first order kinetics. Nanoparticles of cadmium selenide (CdSe) and zinc selenide (ZnSe) have been successfully synthesized by chemical co-precipitation and hydrothermal method. Mercaptoethanol (C 2 H 6 OS), and hydrazine hydrate (N 2 H 4 ) were used as a capping agent to control the size of the nanoparticles (NPs). The structural, UV-optical, morphological studies have been characterized with the help of PXRD, UV, FT-IR, Micro-Raman, HR-TEM and EDAX studies. PXRD is used to calculate the average particle size are found to be ∼1–2 nm for CdSe and ∼16 nm for ZnSe nanoparticles, which have zinc blende phase having cubic structure. HR-TEM images showed that both the samples were agglomerated in spherical shape. Moreover, the presence of functional groups and longitudinal phonon mode were studied by FT-IR and Raman spectral analyzer. Additionally, the optical band gap (E g ) values of CdSe and ZnSe NPs were investigated with the help of UV–Visible diffuse reflectance spectroscopy found to be ∼2.1 eV and ∼2.6 eV, respectively. Further, photocatalytic dye degradation of methylene blue (MB) measured by mixtures of CdSe and ZnSe NPs under 8 W Argon lamp of UV-light irradiation.