Dual S-Scheme Heterojunction CdS/TiO₂/g-C₃N₄ Photocatalyst for Hydrogen Production and Dye Degradation Applications

Abstract

This study investigated a ternary CdS/TiO 2 /g-C 3 N 4 heterojunction for degrading synthetic dyes and hydrogen production from aqueous media through visible light-initiated photocatalytic reactions. CdS, TiO 2 , and g-C 3 N 4 were combined in different mass ratios through a simple hydrothermal method to create CdS/TiO 2 / g-C 3 N 4 composite photocatalysts. The prepared heterojunction catalysts were investigated by using FTIR, XRD, EDX, SEM, and UV−visible spectroscopy analysis for their crystal structures, functional groups, elemental composition, microtopography, and optical properties. The rhodamine B dye was then degraded by using fully characterized photocatalysts. The maximum dye degradation efficiency of 99.4% was noted in these experiments. The evolution rate of hydrogen from the aqueous solution with the CdS/TiO 2 /g-C 3 N 4 photocatalyst remained 2910 μmol• h −1 •g −1 , which is considerably higher than those of g-C 3 N 4 , CdS, CdS/g-C 3 N 4 , and g-C 3 N 4 /TiO 2 -catalyzed reactions. This study also proposes a photocatalytic activity mechanism for the tested ternary CdS/TiO 2 /g-C 3 N 4 heterojunctions.

Synthesis and Catalytic Performance of Mo2C/MoS2 Composite Heterojunction Catalysts

“…Hydrogen has emerged as a paragon of clean energy carriers, embodying a prodigious potential for high energy yield per mass (142 MJ kg −1 ), dwarfing even the venerable fossil fuels, bolstering its prominence at the pinnacles of energy research. The gamut of prevalent hydrogen fabrication techniques encompasses photocatalytic [2,3] and electrolytic hydrogen generation [4][5][6], biomass enzymatic degradation [7,8], and conventional fossilfuel-based hydrogen extraction [9,10]. For example, Marjeta et al [11] synthesized efficient photocatalysts by epitaxial growth of SrTiO 3 on Bi 4 Ti 3 O 12 substrates.…”

Preparation of S-C3N4/AgCdS Z-Scheme Heterojunction Photocatalyst and Its Effectively Improved Photocatalytic Performance

“…As shown in Figure9a, the VB potential of AgCdS is more positive than that of CdS, which makes the oxidation capability of the photoinduced holes generated by AgCdS stronger than that of the photoinduced holes generated by CdS. Many research results have confirmed that the heterojunction system formed by g-C3N4/CdS usually follows the photocatalytic reaction mechanism of Z-scheme[40][41][42][43][44]. Compared to CdS, the CB potential of AgCdS is more positive and closer to the valence band of S-C3N4, making it easier to follow the Z-scheme reaction mechanism in the photocatalytic degradation reaction process.…”