Synthesis and Efficient Visible Light Photocatalytic Hydrogen Evolution of Polymeric g-C₃N₄ Coupled with CdS Quantum Dots

Abstract

Novel CdS quantum dot (QD)-coupled graphitic carbon nitride (g-C 3 N 4 ) photocatalysts were synthesized via a chemical impregnation method and characterized by Xray diffraction, transmission electron microscopy, ultraviolet− visible diffuse reflection spectroscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and photoluminescence spectroscopy. The effect of CdS content on the rate of visible light photocatalytic hydrogen evolution was investigated for different CdS loadings using platinum as a cocatalyst in methanol aqueous solutions. The synergistic effect of g-C 3 N 4 and CdS QDs leads to efficient separation of the photogenerated charge carriers and, consequently, enhances the visible light photocatalytic H 2 production activity of the materials. The optimal CdS QD content is determined to be 30 wt %, and the corresponding H 2 evolution rate was 17.27 μmol•h −1 under visible light irradiation, ∼9 times that of pure g-C 3 N 4 . A possible photocatalytic mechanism of the CdS/g-C 3 N 4 composite is proposed and corroborated by photoluminescence spectroscopy and photoelectrochemical curves.

Can environmental pharmaceuticals be photocatalytically degraded and completely mineralized in water using g-C3N4/TiO2 under visible light irradiation?—Implications of persistent toxic intermediates

“…This unique property and its electric conductivity make it promising for potential applications and theoretical predictions [19][20][21]. Wang et al first used g-C 3 N 4 as a photocatalyst to successfully produce hydrogen [21], and since then, research has explored H 2 evolution and organics degradation [22,23].…”

Hydrothermal Carbonation Carbon-Coated CdS Nanocomposite with Enhanced Photocatalytic Activity and Stability

“…For CdS-PVP and 0.1C/CdS-PVP samples, the weak band around 565 cm −1 indicates -CS 2 wagging (Cd-S stretching) [20]. The bands at 1375 and 1450 cm −1 can be attributed to the Cd-S bonding [21]. Moreover, both samples contain some characteristic peaks of PVP, such as 1283 cm −1 , 1414 cm −1 , and 1658 cm −1 .…”

Chapter Green Nanotechnology: Development of Nanomaterials for Environmental and Energy Applications

“…Other metal oxide and metal sulfide nanomaterials, such as ZnO, Fe 2 O 3 , CdS, and ZnS, have been employed as photocatalysts for the degradation of organic contaminants (12,(44)(45)(46). To synthesize those nanomaterials, various methods, such as chemical bath deposition, hydrothermal treatment, ball milling, and sol-gel method, has been employed.…”