Few-Layer In₂S₃ in Laponite Interlayers: A Colloidal Route Toward Heterostructured Nanohybrids with Enhanced Photocatalysis

Abstract

2D nanomaterials are emerging rapidly because of their exceptional chemical and physical properties. Reducing the thickness or number of crystalline layers improves the catalytic performance of many semiconductors, and thus, different exfoliation strategies have been proposed. However, many exfoliation methods can cause damage or chemical modifications, and control over size and aggregation can be problematic. Herein, In2S3 was grown in the surfactant-modified interlayer space of the layered silicate clay Laponite, leading to a hybrid nanostructure containing 1–1.5 nm thick lamellae of In2S3. The synthetic parameters varied the thickness and regularity of the In2S3 layers, and drastic changes in photophysical properties were observed, underlining the importance of colloidal interactions for templated growth. Photocurrent measurements and photocatalysis experiments showed that more than an order of magnitude increased apparent quantum efficiency and internal photon to current conversion efficiency over In2S3. This was attributed to fast interfacial charge transfer, enhanced redox capability, and improved charge transport properties of the In2S3 layers because of reduced layer thickness and isolation by magnesiosilicate nanoclay in between. Overall, this study provides a simple colloidal approach to grow defined layered heterostructures of In2S3 with limited thickness and enhanced photophysical properties, allowing improved catalysis. The photocatalytic enhancement, facile synthesis, and increased product yield compared with pure In2S3 make these promising materials for energy conversion and environmental remediation.

Few-Layer ZnIn2S4/Laponite Heterostructures: Role of Mg2+ Leaching in Zn Defect Formation

“…Herein, few-layer Zn-defective ZnIn 2 S 4 was synthesized in the organically modified interlayer of Lap. While the layered nanostructures of these hybrids resembled those of previously reported In 2 S 3 -Lap hybrids, 25 the occurrence of Zn defects gave a unique color and broadband absorption, providing the motivation for further study of the origins of this effect. Since zinc (Zn 2+ ) and magnesium (Mg 2+ ) ions have similar ionic radii (0.074 and 0.072 nm, respectively), leached Mg 2+ from the octahedral layer of Lap could partially replace Zn in ZnIn 2 S 4 to form Zn defects.…”

“…Recently, Laponite-RD (Lap), a layered silicate clay with a thickness of 0.92 nm and ∼25 nm diameter with an anionic basal surface, has been shown to be useful for the development of colloidal assemblies and layered materials. − Furthermore, its high charge and surface area allow facile modification of the interlayer space, making it the focus of previous research on templated growth of nanomaterials. , “Pillaring” with cationic surfactants can provide both an increased interlayer spacing and a hydrophobic cavity which is conducive to the growth of layered nanomaterials. One important consideration for templated synthesis using Lap is the leaching of magnesium ions (Mg 2+ ) from the octahedral layer at low Lap concentrations (below 1.6% by weight), which destroys the charge balance and structure .…”

Facet Engineering of Bismuth Molybdate via Confined Growth in a Nanoscale Template toward Water Remediation

“…The morphologies of these PLB samples were anisotropic, elongated, and up to microns in length, whereas BMO synthesized with only CTAB formed square sheets with 50–100 nm edge lengths. This contrasts with syntheses of MoS 2 , In 2 S 3 , and ZnIn 2 S 4 in the pillared Lap interlayer, in which thin semiconductor layers formed a heterolayered structure. Interestingly, CTAB-modified Lap was found to alter the growth orientation of BMO crystals, promoting preferential growth along the [010] direction, which otherwise does not occur in the BMO control.…”

“…This results in an expanded interlayer space, the size of which is also dependent on the length of the hydrocarbon tail of the exchanged entity . As a consequence of their high surface area and surface charge, pillared clays have been shown to strongly adsorb dyes and heavy metal cations. , The expanded, organophilic interlayer space in pillared Lap has opened up an avenue for the growth of nanoscopic layered materials in the intergallery space. − …”

Direct Z-Scheme Photocatalytic System: Insights into the Formative Factors of Photogenerated Carriers Transfer Channel from Ultrafast Dynamics

“…For example, X 2 Y 3 (X: Al, Ga, In. Y: S, Se, Te) ferroelectrics possessing the vertical intrinsic electric fields can significantly affect the IEF after forming heterostructures, which facilitates the evaluation of the role of the electric field on the Z-scheme pathway. − BCN, complementary to graphene and BN, possesses a strong adaptable property in constructing heterostructures due to the tunable electronic structures, good mechanical behavior, and thermal stability. − …”