Efficient light-driven hydrogen evolution and azo dye degradation over the GdVO₄@g-C₃N₄ heterostructure

Abstract

A straightforward hydrothermal technique was used for the synthesis of a g-C3N4/GdVO4 (CN/GdV) heterostructure as an alternate material for energy and environmental applications.

Construction of type II ZnBi2O4/g-C3N4 heterojunction photocatalysts for efficient degradation of acid red B

“…5b, and the three characteristic peaks fitted at 284.8 eV, 286.1 eV, and 288.7 eV are attributed to the sp 2 hybridized C–C bond, the sp 3 hybridized C–(N) 3 bond, and the sp 2 hybridized N–CN bond, respectively. 36,37 This suggests that g-C 3 N 4 is present in the composite material. It can be seen that the peak intensity of the C 1s of ZBN is significantly lower than that of pure g-C 3 N 4 , which may be because there is only a little amount of g-C 3 N 4 in the main body of ZBN.…”

“…Under UV light, the electrons in g-C 3 N 4 and ZnBi 2 O 4 leap to the conduction band and form holes in the valence band, while the g-C 3 N 4 has a more positive valence band potential than that of ZnBi 2 O 4 , so the holes in g-C 3 N 4 can easily migrate to the valence band of ZnBi 2 O 4 . Since the valence band potential of ZnBi 2 O 4 is more negative than that of H 2 O/˙OH (2.27 eV), 37 it cannot produce ˙OH. The conduction band potential of ZnBi 2 O 4 is more negative than that of g-C 3 N 4 , and electrons from ZnBi 2 O 4 will migrate to the conduction band of g-C 3 N 4 , which is more negative than that of O 2 /˙O 2 − (−0.33 eV), 60 so the conduction band electrons react with the oxygen adsorbed on the surface of the composite catalyst to form ˙O 2 − , and the resulting ˙O 2 − has a strong oxidizing ability for acid red B, which eventually decomposes acid red B mineralization to CO 2 , H 2 O and other small molecules.…”

Efficient Zinc Vanadate Homojunction with Cadmium Nanostructures for Photocatalytic Water Splitting and Hydrogen Evolution

“…It can be deconvoluted into two peaks 401.9 and 408.69 eV, ascribed to the Cd 3d5/2 and Cd 3d3/2 spin states, respectively, which are the characteristics of the Cd 2+ oxidation state [44]. Figure 6b displays the high-resolution spectra of the V 2p core level and can be deconvoluted into two peaks 514 and 521.09 eV attributed to V2p3/2 and V2p1/2, respectively, which are the characteristics of V 4+ and V 5+ oxidation states [28]. Figure 6c displays the high-resolution spectra of the O 1s core level and is deconvoluted into three peaks 527.01, 527.55, and 529.46 eV associated with V-O and Zn-O/Cd-O, along with a large number of defect sites [17].…”

“…Interestingly, low-band-gap semiconductors effectively break water into hydrogen and oxygen, as most of the semiconductors with large band gaps are UV-active [16][17][18][19][20][21][22][23]. Recently, a few research groups have synthesized various vanadate materials and their composites and have employed them in environmental remediation and hydrogen production [25][26][27][28][29]. Expanding the utility of ZnV as a photocatalyst for H 2 production necessitates augmenting its charge transfer pathways to mitigate the charge transfer recombination within the photocatalyst and thereby increasing the overall efficiency [28][29][30].…”

“…Recently, a few research groups have synthesized various vanadate materials and their composites and have employed them in environmental remediation and hydrogen production [25][26][27][28][29]. Expanding the utility of ZnV as a photocatalyst for H 2 production necessitates augmenting its charge transfer pathways to mitigate the charge transfer recombination within the photocatalyst and thereby increasing the overall efficiency [28][29][30]. There are various research studies that have explored the strategies to enhance the photocatalytic efficacy of the materials by accelerating the segregation of charge carriers.…”