scholarly journals Photocatalytic Hydrogen Production from Water on Ga, Sn-Doped ZnS under Visible Light Irradiation

2014 ◽  
Vol 925 ◽  
pp. 200-204
Author(s):  
Leny Yuliati ◽  
Melody Kimi ◽  
Mustaffa Shamsuddin
Keyword(s):  
Photocatalytic Activity ◽  
Hydrogen Production ◽  
Visible Light ◽  
Band Gap ◽  
Visible Light Irradiation ◽  
Absorption Edge ◽  
Band Gap Energy ◽  
Light Irradiation ◽  
Photocatalytic Hydrogen Production ◽  
Gap Energy

Zinc sulfide (ZnS) has been reported to act as a photocatalyts to reduce water to hydrogen. However, ZnS could not work under visible light irradiation due to its large band gap energy. In order to improve the performance of ZnS, Ga and Sn were doped to ZnS. The series of Ga (0.1),Sn (x)-ZnS with various amounts of Sn (x) was prepared by hydrothermal method. XRD patterns suggested that the addition of Ga might reduce the crystallinity of ZnS, suggesting that Ga might inhibit the crystal growth or agglomeration of ZnS. On the other hand addition of Sn did not much affect the structure of the Ga (0.1)-ZnS. The DR UU-visible spectra confirmed the red shift of the absorption edge with the addition of Ga due to the reduced band gap energy, while the addition of Sn did not much shift the absorption edge of the Ga (0.1)-ZnS to longer wavelength. FESEM images showed that all the prepared samples have sphere-shaped particles and no remarkable change was observed with the addition of Ga or Sn. The photocatalytic hydrogen production from water was carried out at room temperature in the presence of sacrificial agent under visible light irradiation. While ZnS did not show activity under visible light, all the prepared Ga (0.1)-ZnS and Ga (0.1),Sn (x)-ZnS samples exhibited photocatalytic activity for hydrogen production. The highest hydrogen production was achieved on Ga (0.1),Sn (0.01)-ZnS, which activity was ca. three times higher than that of the single doped Ga (0.1)-ZnS. This study clearly showed that Sn acted as a good co-dopant to increase the photocatalytic activity of Ga (0.1)-ZnS for hydrogen production from water under visible light irradiation.

Improving the photocatalytic hydrogen production of Ag/g-C3N4 nanocomposites by dye-sensitization under visible light irradiation

Nanoscale ◽  
2016 ◽  
Vol 8 (4) ◽  
pp. 2249-2259 ◽  
Author(s):  
Jiayi Qin ◽  
Jingpei Huo ◽  
Piyong Zhang ◽  
Jian Zeng ◽  
Tingting Wang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Hydrogen Production ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Dye Sensitization ◽  
Photocatalytic Hydrogen Production

Fluorescein-sensitized Ag/g-C3N4 nanocomposites have a remarkably enhanced photocatalytic activity for hydrogen production under visible light.

N-Loaded TiO2 for Photocatalytic Degradation of Methyl Orange under Visible Light Irradiation

2012 ◽  
Vol 622-623 ◽  
pp. 883-888
Author(s):  
Natkritta Boonprakob ◽  
Natda Wetchakun ◽  
Sukon Phanichphant ◽  
Jun Chen ◽  
Burapat Inceesungvorn
Keyword(s):  
Methyl Orange ◽  
Visible Light ◽  
Band Gap ◽  
Visible Light Irradiation ◽  
Sol Gel ◽  
Band Gap Energy ◽  
Light Irradiation ◽  
Gap Energy ◽  
Visible Light Driven ◽  
Degradation Of Methyl Orange

Nitrogen-loaded TiO2(N-loaded TiO2), a visible-light driven catalyst, was successfully synthesized by the modified sol-gel method. Physical characterizations of the as-prepared catalysts have been performed by using X-ray diffraction (XRD), Diffuse reflectance UVvisspectroscopy(DRUVvis), Raman spectroscopyand BETspecific surface areain order to obtain structure-activity relationship. Results from Raman spectroscopy clearly suggested that N atoms were incorporated into the TiO2crystal lattice as evidenced by the vibrational peak of TiN in TiO2-xNx.DR UVvis results also suggested that the nitrogen dopant might be responsible for narrowing the TiO2band gap energy, thus resulting in a shift towards the visiblelight region. Photocatalytic activity of N-loaded TiO2evaluated through the degradation of methyl orange (MO)under visible light irradiation (l> 400 nm) indicated that all N-loaded photocatalysts exhibited significantly higher activities than the unloaded TiO2and Degussa P25 TiO2. According to the results from DR UV-vis, XRD and BET studies, the enhanced photoactivity observed from N-loaded samples might be due to a decrease in TiO2band gap energy and/or changes in chemical and physical properties of the materials upon loading with nitrogen.

Photocatalytic Degradation of Methylene Blue over Co-Ag3VO4 under Visible Light Irradiation

2011 ◽  
Vol 335-336 ◽  
pp. 1385-1390 ◽  
Author(s):  
Shuo Wiei Zhao ◽  
Hui Xu ◽  
Hua Ming Li ◽  
Yuan Guo Xu
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Absorption Edge ◽  
Diffuse Reflectance Spectroscopy ◽  
Dye Degradation ◽  
Light Irradiation ◽  
Experimental Conditions ◽  
X Ray

In order to improve the photocatalytic activity, Co was successfully loaded into Ag3VO4 by using impregnation process. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS) and diffuse reflectance spectroscopy (DRS). The XRD and SEM–EDS analyses revealed that Co ion was dispersed on Ag3VO4. The DRS results indicated that the absorption edge of the Co–Ag3VO4 catalyst shifted to longer wavelength. The enhanced photocatalytic activity of Co–Ag3VO4 for Methylene Blue(MB) dye degradation under visible light irradiation was due to its wider absorption edge and higher separation rate of photo-generated electron and holes. In the experimental conditions, it is demonstrated that the MB was effectively degraded by more than 95% within 40 min when the Co–Ag3VO4 catalyst was calcined at 300°C with 1 wt.% Co content.

scholarly journals Photocatalytic Hydrogen Production from Glycerol Aqueous Solution Using Cu-Doped ZnO under Visible Light Irradiation

2019 ◽  
Vol 9 (13) ◽  
pp. 2741 ◽  
Author(s):  
Vincenzo Vaiano ◽  
Giuseppina Iervolino
Keyword(s):  
Hydrogen Production ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Noble Metals ◽  
Light Irradiation ◽  
Precipitation Method ◽  
Glycerol Solution ◽  
Glycerol Concentration ◽  
Photocatalytic Hydrogen Production ◽  
Doped Zno

Cu-doped ZnO photocatalysts at different Cu loadings were prepared by a precipitation method. The presence of Cu in the ZnO crystal lattice led to significant enhancement in photocatalytic activity for H2 production from an aqueous glycerol solution under visible light irradiation. The best Cu loading was found to be 1.08 mol %, which allowed achieving hydrogen production equal to 2600 μmol/L with an aqueous glycerol solution at 5 wt % initial concentration, the photocatalyst dosage equal to 1.5 g/L, and at the spontaneous pH of the solution (pH = 6). The hydrogen production rate was increased to about 4770 μmol/L by increasing the initial glycerol concentration up to 10 wt %. The obtained results evidenced that the optimized Cu-doped ZnO could be considered a suitable visible-light-active photocatalyst to be used in photocatalytic hydrogen production without the presence of noble metals in sample formulation.

Photochemical preparation of Cd/CdS photocatalysts and their efficient photocatalytic hydrogen production under visible light irradiation

2014 ◽  
Vol 16 (5) ◽  
pp. 2728-2735 ◽  
Author(s):  
Qizhao Wang ◽  
Jiajia Li ◽  
Yan Bai ◽  
Juhong Lian ◽  
Haohao Huang ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Photocatalytic Hydrogen Production ◽  
Cadmium Ions

A certain amount of Na2S2O3·5H2O solution added to the solution containing cadmium ions to form Cd/CdS photocatalysts could remove cadmium ions and produce hydrogen efficiently under visible light irradiation.

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