Constructing Direct Z‐Scheme Heterostructure by Enwrapping ZnIn₂S₄ on CdS Hollow Cube for Efficient Photocatalytic H₂ Generation

Abstract

Rational design hybrid nanostructure photocatalysts with efficient charge separation and transfer, and good solar light harvesting ability have critical significance for achieving high solar-to-chemical conversion efficiency. Here a highly active and stable composite photocatalyst is reported by integrating ultrathin ZnIn 2 S 4 nanosheets on surface of hollow CdS cube to form the cube-in-cube structure. Experimental results combined with density functional theory calculations confirm that the Z-scheme ZnIn 2 S 4 /CdS heterojunction is formed, which highly boosts the charge separation and transfer under the local-electric-field at semiconductor/semiconductor interface, and thus prolongs their lifetimes. Moreover, such a structure affords the highly enhanced light-harvesting property. The optimized ZnIn 2 S 4 /CdS nanohybrids exhibit superior H 2 generation rate under visible-light irradiation (𝝀 ≥ 420 nm) with excellent photochemical stability during 20 h continuous operation.

Synergy of Cd Doping and S Vacancies in CdxZn1–xIn2S4 Hierarchical Nanotubes for Highly Improved Visible-Light-Driven H2 Evolution

“…The survey spectra in Figure a reveal that both ZIS and C 0.09 ZIS NTs consist of Zn, In, and S elements, and the extra Cd signals observed for C 0.09 ZIS NTs are caused by Cd-doping. For ZIS NTs, the Zn 2p doublet peaks at 1023.10 and 1046.15 eV (Figure b) are attributable to Zn 2+ ions, , while the In 3d doublet peaks around 445.35 and 452.79 eV (Figure c) indicate the presence of In 3+ species. , Meanwhile, the S 2p spectrum of ZIS NTs can be fitted into two peaks at 162.26 and 163.37 eV (Figure d), in agreement with that of the S 2– valence state. , Regarding C 0.09 ZIS NTs, the Cd 3d spectrum exhibits the doublet signals at 405.35 and 412.10 eV (Figure S7), corresponding to the Cd 2+ ions. , In comparison with ZIS NTs, the C 0.09 ZIS NTs present negative shifts of about 0.63, 0.34, and 0.51 eV for Zn 2p, In 3d, and S 2p spectra, which signifies the increased electron cloud densities of Zn, In, and S atoms of the latter . The lowered Zn 2p and In 3d binding energies of C 0.09 ZIS NTs could originate from the formation of S vacancies which minify the coordination number of Zn and In atoms, , leading to their raised electron cloud densities.…”

“…43,44 Regarding C 0.09 ZIS NTs, the Cd 3d spectrum exhibits the doublet signals at 405.35 and 412.10 eV (Figure S7), corresponding to the Cd 2+ ions. 45,46 In comparison with ZIS NTs, the C 0.09 ZIS NTs present negative shifts of about 0.63, 0.34, and 0.51 eV for Zn 2p, In 3d, and S 2p spectra, which signifies the increased electron cloud densities of Zn, In, and S atoms of the latter. 47 The lowered Zn 2p and In 3d binding energies of C 0.09 ZIS NTs could originate from the formation of S vacancies which minify the coordination number of Zn and In atoms, 48,49 leading to their raised electron cloud densities.…”

Dual-Functional CuO-Decorated Bi3.84W0.16O6.24/Bi2WO6 Nanohybrids for Enhanced Electrochemical Hydrogen Evolution Reaction and Photocatalytic Cr(VI) Reduction Performance

“…This increased binding energy was likely due to a decreased electron concentration on the biphase-BW part of the hybrid, which could have been induced due to electron transfer from biphase-BW to CuO, as it was also confirmed in the mechanism. 36 The core spectrum of copper produces strong peaks at 933.93 and 953.58 eV that are ascribed to Cu 2p 3/2 and Cu 2p 1/2 signals of Cu 2+ , which confirms the formation of CuO (Figure 4d). The O 1s core-level spectrum of CuO/biphase-BW can be deconvoluted into three peaks appearing at 529.4, 530.1, and 532.1 eV belonging to the lattice oxygen (O latt ) in CuO/biphase-BW, the oxygen defect states and adsorbed oxygen (O ads ) from the atmosphere, respectively (Figure 4e).…”

Designing Atomic Interfaces in Chalcogenides for Boosting Photocatalysis

“…Reproduced with permission. [ 27 ] Copyright 2022, Wiley‐VCH. b) Type II interface, the picture provided is a selected experimental case to additionally explain the type II interface.…”

“…d) The Z-scheme interfacial charge transport and the integral effect of ZnIn 2 S 4 /CdS photocatalyst. Reproduced with permission [27]. Copyright 2022, Wiley-VCH.…”