Polyoxometalate‐Decorated g‐C₃N₄‐Wrapping Snowflake‐Like CdS Nanocrystal for Enhanced Photocatalytic Hydrogen Evolution

Abstract

Photocatalytic hydrogen evolution technology is recognized as a promising approach to relieving the growing energy crisis. Therefore, the development of a stable high-performance photocatalyst has long been the focus of research. In this work, quaternary composite materials involving a snowflake-like CdS nanocrystal wrapped by different amounts of polyoxometalate-decorated g-C N and polypyrrole (GPP@CdS) have been synthesized as photocatalysts for hydrogen production under visible-light irradiation. It has been revealed that the best composite (40 % GPP@CdS composite) exhibits hydrogen production activity of 1321 μmol, which exceeds that of CdS by a factor of more than two, and can be used in at least seven cycles with negligible loss of activity. The enhanced photocatalytic performance has been primarily attributed to the efficient synergy of CdS, g-C N , polypyrrole (PPy), and the polyoxometalate Ni (PW ) . It should be noted that the introduction of PPy and g-C N into the title composite simultaneously promotes electron/hole pair separation and photocatalytic stability, whereas Ni (PW ) serves as an efficient electron modulator and extra catalytic active site.

Point‐to‐face contact heterojunctions: Interfacial design of 0D nanomaterials on 2D g‐C3N4 towards photocatalytic energy applications

“…189 Also, the flexible electronic structure of g-C 3 N 4 nanosheets as well as their robust stability and fast charge transfer drastically accelerates the separation of the electron-hole pairs in CdS, thus preventing photocorrosion and enhancing photoredox reaction efficiency. 200 Thence, the combination of CdS and g-C 3 N 4 is mutually benefiting each other from their drawbacks of low light harvesting ability and fast charge recombination, respectively. Shao et al 199 successfully loaded 0D CdS doped with nitrogen-doped hollow carbon spheres (CdS-NHC) onto g-C 3 N 4 nanosheets by mechanical stirring (Figure 11E).…”

“…In general, due to exceptional photocatalytic characteristics, CdS has been regarded as one of the most attractive photocatalysts for hybridization with g‐C 3 N 4 nanosheets 189 . Also, the flexible electronic structure of g‐C 3 N 4 nanosheets as well as their robust stability and fast charge transfer drastically accelerates the separation of the electron–hole pairs in CdS, thus preventing photocorrosion and enhancing photoredox reaction efficiency 200 . Thence, the combination of CdS and g‐C 3 N 4 is mutually benefiting each other from their drawbacks of low light harvesting ability and fast charge recombination, respectively.…”

Interfacial engineering of graphitic carbon nitride (g-C3N4)-based metal sulfide heterojunction photocatalysts for energy conversion: A review

“…Nevertheless, for bare g-C3N4, it is still restricted by the low efficiency attributed to the rapid recombination rate of charge carries, which impedes their widely use in practical applications. Sulfide semiconductors are vastly pursued by researchers to engineer hybrid structures with g-C3N4 for their appealing attributes [130,[280][281][282][283]. In line with the focus of this review for artificial photosynthesis, we will present the photocatalytic water splitting for H2 evolution (Section 4.1) [91,216,[284][285][286][287], photocatalytic CO2 reduction (Section 4.2) [254,[288][289][290][291][292] and photocatalytic N2 fixation (Section 4.3) [293][294][295] in this section.…”

Advantageous Interfacial Effects of AgPd/g‐C3N4 for Photocatalytic Hydrogen Evolution: Electronic Structure and H2O Dissociation

“…[4][5][6] It has been re-ported that the fabricationo fo rganic conjugated polymers is one effective strategy,t hanks to the advantages of stabilityi n aqueous solution, visible light absorption, intramolecular charge transfer,l ow cost, and so on. [5][6][7][8][9][10][11][12] Graphitic carbon nitride (g-C 3 N 4 ), with its well-known physiochemicals tability,n arrow bandgap, attractive electronic properties, and environmental friendliness,h as become ap romising two-dimensional nonmetal material for many photocatalytic applicationss uch as water splitting, CO 2 reduction, and environmental contaminant removal. [13][14][15][16] In addition, g-C 3 N 4 can be used as af lexible support to encapsulate nanocrystals, resulting in the stabilization of nanocrystals and enhanced photocatalytic performance.…”

“…The conversion efficiency relies significantly on materials that can utilize photon energy from the wide solar spectrum, separate electron–hole pairs, and promote charge carrier diffusion . It has been reported that the fabrication of organic conjugated polymers is one effective strategy, thanks to the advantages of stability in aqueous solution, visible light absorption, intramolecular charge transfer, low cost, and so on …”