High-efficient Degradation of Dyes by Zn_xCd_1−xS Solid Solutions under Visible Light Irradiation

Abstract

Nanocrystal Zn x Cd1−x S solid solutions were successfully and simply prepared by hydrothermal processes using stable, less toxic, inorganic salts Cd(Ac)2, Zn(Ac)2, and Na2S as the reactants. The band gap of the solid solutions can be tuned by changing constituent stoichiometries of Cd and Zn. With the increase of Cd molar fraction, the X-ray diffraction peaks of the Zn x Cd1−x S nanocrystals gradually shifted to small angle. Using photocatalytic degradation of methyl orange as model reactions in the aqueous phase under visible light irradiation (λ > 420 nm), the samples prepared at the condition (Cd/Zn = 3:1, 160 °C, 16 h) possessed the best activity. The diameter of the particles was about 15 nm. Transmission electron microscopy showed the particles were spherical and homogeneous. The photocatalytic conversion was up to 96% and was obviously superior to CdS and TiO2−x N x degradation under identical conditions. Liquid chromatogram/mass spectrometery was used to test the degradation products. X-ray photoelectron spectroscopy detected the valence state of elements in the samples before and after the degradation. At the same time, their degradation of p-hydroxyazobenzene, rhodamine B, and congo red also achieved good effect.

Self-Assembled ZnIn0.16Ag2x S1.24+x (x = 0–0.025) Nanospheres by a Simple Hydrothermal Method as Visible Light-Driven Photocatalysts

“…The nanoparticles were still sphere. The similar phenomenon also occurs on Zn x Cd 1-x S solid solutions [22]. Then the Zn:In:Ag metal composition ratio after hydrogen evolution was found to be 1:0.16:0.03 by ICP which was close to that of before hydrogen evolution.…”

Investigation of nitrogen doped and carbon species decorated TiO2 with enhanced visible light photocatalytic activity by using chitosan

“…Fig. 2(b) shows the band gap energy (E g ) of the as-prepared TiO 2 and Cts/TiO 2 -25, which is calculated by the equation of (F(R)E) 1/2 = A(E-E g ) [43]. The estimated E g values of the as-prepared TiO 2 and Cts/TiO 2 -25 are 3.16 eV and 2.88 eV, respectively.…”

Synthesis of sulphur doped bismuth selenide photocatalysts by the solvothermal method and their photocatalytic activities under visible-light irradiation

“…The second approach is the regulation of band-gap energies by making a compound of two different semiconductors with wide and narrow band-gaps [2,3,5,[11][12][13]. The third approach is the building up of a valence band in a more negative position [14][15][16][17][18]. Based on these, the current study synthesized S-doped BiSe by the solvothermal method in ethanediamine solvent.…”