Ultrathin ZnIn₂S₄ Nanosheets Anchored on Ti₃C₂T_X MXene for Photocatalytic H₂ Evolution

Abstract

Photocatalysts derived from semiconductor heterojunctions that harvest solar energy and catalyze reactions still suffer from low solar‐to‐hydrogen conversion efficiency. Now, MXene (Ti3C2TX) nanosheets (MNs) are used to support the in situ growth of ultrathin ZnIn2S4 nanosheets (UZNs), producing sandwich‐like hierarchical heterostructures (UZNs‐MNs‐UZNs) for efficient photocatalytic H2 evolution. Opportune lateral epitaxy of UZNs on the surface of MNs improves specific surface area, pore diameter, and hydrophilicity of the resulting materials, all of which could be beneficial to the photocatalytic activity. Owing to the Schottky junction and ultrathin 2D structures of UZNs and MNs, the heterostructures could effectively suppress photoexcited electron–hole recombination and boost photoexcited charge transfer and separation. The heterostructure photocatalyst exhibits improved photocatalytic H2 evolution performance (6.6 times higher than pristine ZnIn2S4) and excellent stability.

Progressively stimulating carrier motion over transient metal chalcogenide quantum dots towards solar-to-hydrogen conversion

“…For example, O-terminated Ti 3 C 2 (O-Ti 3 C 2 ) as a representative MXene showed a near-zero Gibbs free energy for the photocatalytic production of hydrogen. 15,18 Therefore, MNs as co-catalysts are signicantly benecial for introducing enriched reaction sites, decreasing the over-potential, and prolonging the charge lifetime of catalysts. Given the structural merits of MNs as a charge mediator, TMC QDs as lightharvesting antennas and metallic ion dopants as energy band modulators, we speculated that designing MN-encapsulated metal ion doped-TMC QD photosystems would synergistically enable highly efficient unidirectional charge migration pathways and boosted charge separation efficiency.…”

Thin In‐Plane In2O3/ZnIn2S4 Heterostructure Formed by Topological‐Atom‐Extraction: Optimal Distance and Charge Transfer for Effective CO2 Photoreduction

“…However, the EPR signal of DMPO-•OH can be observed for the aqueous suspension of in-plane In 2 O 3 /HZIS or pure In 2 O 3 , and the appearance of DMPO-•OH signal from in-plane In 2 O 3 /HZIS suggests that the photo-generated holes remain in the valence band (VB) of In 2 O 3 and do not transfer to the VB of HZIS. [21] As can be seen from Figure 2c, both the in-plane and the out-plane In 2 O 3 /HZIS heterostructures are S-scheme heterojunctions. [22]…”

“…[16b,20] On the electrochemical impedance spectra (EIS), the in-plane In 2 O 3 /HZIS heterostructure shows a smaller arc radius than pristine HZIS (Figures S9-S11, Supporting Information) thanks to the better electrical conductivity of In 2 O 3 . [21] The selective extraction of Zn from the HZIS, which takes place via reaction (1), occurs because Zn(NH 3 ) x has a significantly higher the coordination constant (lgβ n ) than In(NH 3 ) x (Figure 1h). Upon the extraction of Zn, the residual In atoms in the NSs are hydrolyzed under the alkaline NH 3 •H 2 O environment to generate In 2 O 3 , which is then incorporated into the framework of the HZIS NSs (Figure 1g).…”

“…Both the in-plane and out-plane In 2 O 3 /HZIS heterostructure show smaller arc radius than pristine HZIS in the EIS (Figure S11, Supporting Information), thanks to the good electrical conductivity of In 2 O 3 . [21] As a result, the transient photocurrent response becomes a more straightforward measure of the photo-excited charge carriers.…”

Pyroelectric Catalysis-Based “Nano-Lymphatic” Reduces Tumor Interstitial Pressure for Enhanced Penetration and Hydrodynamic Therapy

“…Because of the difference of Fermi level (E f ) and work function between CdS and MXene, the negative charges of CdS transferred to MXene to equilibrate the E f between the two materials. 34 During the equilibrium process, the energy band of CdS (n-type semiconductor) was bent upward to generate the Schottky barrier. MXene converted the light to hyperpyrexia with laser irradiation.…”