Detection of Oxygen Species Generated in the Presence of CNT by Loading ZnS

Abstract

ZnS-CNT nanocomposites were synthesized using simple cheap and less toxic ZnCl₂ as the zinc (II) precursor. The prepared nanoparticles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV–vis diffuse reflectance spectra. XRD and TEM results indicate that the prepared product is ZnS nanoparticles and has a grain size of 30 nm in diameter. DRS show that ZnS-CNT possesses the absorption profile across the whole visible-light region. The generation of reactive oxygen species were detected through the oxidation reaction from 1,5-diphenyl carbazide to 1,5-diphenyl carbazone. It is found that the photocurrent density and the photocatalytic effect increase in the case with the modified ZnS. Excellent catalytic degradation of methylene blue solution was observed using the ZnS-CNT composites under visible light irradiation. It is proposed that both the strong visible-light absorption and the multiple exciton excitations contribute to the high visible-light photocatalytic activity.

Keywords:

• ZnS
• 1,5-diphenyl carbazide (DPCI)
• visible light
• oxygen species
• TEM