Synthesis and characterization of ZnS with controlled amount of S vacancies for photocatalytic H2 production under visible light
نویسندگان
چکیده
Controlling amount of intrinsic S vacancies was achieved in ZnS spheres which were synthesized by a hydrothermal method using Zn and S powders in concentrated NaOH solution with NaBH4 added as reducing agent. These S vacancies efficiently extend absorption spectra of ZnS to visible region. Their photocatalytic activities for H2 production under visible light were evaluated by gas chromatograph, and the midgap states of ZnS introduced by S vacancies were examined by density functional calculations. Our study reveals that the concentration of S vacancies in the ZnS samples can be controlled by varying the amount of the reducing agent NaBH4 in the synthesis, and the prepared ZnS samples exhibit photocatalytic activity for H2 production under visible-light irradiation without loading noble metal. This photocatalytic activity of ZnS increases steadily with increasing the concentration of S vacancies until the latter reaches an optimum value. Our density functional calculations show that S vacancies generate midgap defect states in ZnS, which lead to visible-light absorption and responded.
منابع مشابه
Synthesis and characterization of visible light active S-doped TiO2 nanophotocatalyst
S-doped and bare mesoporous TiO2 were prepared using titanium tetraisopropoxide and thiocarbamide as raw materials. Prepared materials were characterized by means of fourier transform infrared spectroscopy FT-IR, thermogravimetry-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), UV–Vis absorption spectroscopy, Brunauer–Emmett–Teller (BET) specific surface area and Barrett–Joy...
متن کاملSynthesis and characterization of visible light active S-doped TiO2 nanophotocatalyst
S-doped and bare mesoporous TiO2 were prepared using titanium tetraisopropoxide and thiocarbamide as raw materials. Prepared materials were characterized by means of fourier transform infrared spectroscopy FT-IR, thermogravimetry-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), UV–Vis absorption spectroscopy, Brunauer–Emmett–Teller (BET) specific surface area and Barrett–Joy...
متن کاملSynthesis, Characterization, and Application of Zr,Ce-TiO2/SiO2 Nanocomposite Thin Film as Visible-light Active Photocatalyst
A novel Zr,Ce-TiO2/SiO2 nanocomposite thin film was successfully prepared with various amounts of Zr4+ and Ce4+ as codopant ions for self-cleaning applications. A thin film was coated on a tile substrate by dip-coating and porous Zr,Ce-TiO2/SiO2 was obtained after heat treatment for 2 hours at 500 °C. The SEM images an...
متن کاملPhoto-degradation of Methylene Orange by zinc-sulfide nanoparticles synthesized via hydrothermal method
Background and Objective: In the present research, the synthesis and characterization of ZnS nanoparticles in zinc blend crystallite phase via hydrothermal method were reported. Advanced oxidation processes using nanophotocatalysts are one of the most efficient methods for removing the dyes with complex organic compounds from textile and industrial wastewaters. The photocatalytic performance of...
متن کاملSynthesis and Characterization of Ni0.5Cu0.5Cr2O4 Nanostructure for Discoloration of Aniline Dye under Visible Light from Wastewater
In this research, pure-phased Ni0.5Cu0.5Cr2O4 synthesis via solid-state method successfully. In the other part, the photocatalytic activity of synthesized Ni0.5Cu0.5Cr2O4 was investigated in various aspects by using Malachite green as a pollutant and compared with the number of previous photocatalysts. T...
متن کامل