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 ◽  
...  

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

2014 ◽  
Vol 925 ◽  
pp. 200-204
Author(s):  
Leny Yuliati ◽  
Melody Kimi ◽  
Mustaffa Shamsuddin

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.


2019 ◽  
Vol 9 (13) ◽  
pp. 2741 ◽  
Author(s):  
Vincenzo Vaiano ◽  
Giuseppina Iervolino

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.


2014 ◽  
Vol 16 (5) ◽  
pp. 2728-2735 ◽  
Author(s):  
Qizhao Wang ◽  
Jiajia Li ◽  
Yan Bai ◽  
Juhong Lian ◽  
Haohao Huang ◽  
...  

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.


2017 ◽  
Vol 5 (4) ◽  
pp. 1387-1393 ◽  
Author(s):  
Wenhui Feng ◽  
Zhibin Fang ◽  
Bo Wang ◽  
Lulu Zhang ◽  
Yan Zhang ◽  
...  

Unique grain boundary-rich organic–inorganic hybrid D-ZnS(en)0.5 nanosheets exhibit superior activity for photocatalytic H2 evolution under visible light irradiation.


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