Microwave-assisted synthesis of polyoxometalate-Dy2O3 monolayer nanosheets and nanotubes.

Two-dimensional (2D) materials have shown unique chemical and physical properties; however, their synthesis is highly dependent on the layered structure of building blocks. Herein, we developed monolayer Dy2O3-phosphomolybdic acid (PMA) nanosheets and nanotubes based on microwave synthesis. Microwave-assisted synthesis with high-energy input gives a faster and dynamically driven growth of nanomaterials, resulting in high-purity nanostructures with a narrow size distribution. The reaction times of the nanosheets and nanotubes under microwave synthesis are significantly reduced compared with oven-synthesis. Dy2O3-PMA nanosheets and nanotubes exhibit enhanced activity and stability in photoconductance, with higher sensitivities (0.308 µA cm-2 for nanosheets and 0.271 µA cm-2 for nanotubes) compared to the individual PMA (0.12 µA cm-2) and Dy2O3 (0.025 µA cm-2) building blocks. This work demonstrates the promising application potential of microwave-synthesized 2D heterostructures in superconductors and photoelectronic devices.

Tuning the Chirality Evolution in Achiral Subnanometer Systems by Judicious Control of Molecule Interactions.

Chirality evolution from molecule levels to the nanoscale in an achiral system is a fundamental issue that remains undiscovered. Here, we report the assembly of polyoxometalate (POM) clusters into chiral subnanostructures in achiral systems by programmable single-molecule interactions. Driven by the competing binding of Ca2+ and surface ligands, POM assemblies would twist into helical nanobelts, nanorings, and nanotubes with tunable helicity. Chiral molecules can be used to differentiate the formation energies of chiral isomers and immobilize the homochiral isomer, where strong circular dichroism (CD) signals are obtained in both solutions and films. Chiral helical nanobelts can be used as circularly polarized light (CPL) photodetectors due to their distinct chiroptic responsivity for right and left CPL. By the fine-tuning of interactions at single-molecule levels, the morphology and CD spectra of helical assemblies can be precisely controlled, providing an atomic precision model for investigation of the structure-chirality relationship and chirality manipulation at the nanoscale.

Visible Light Induced Ag-Polyoxometalate Coassembly into Single-Cluster Nanowires.

1D superlattices with long-ranged periodicity present extraordinary application properties due to their unique electronic structures. Here, the visible light driven synthesis of 1D single-cluster chains constructed by polyoxometalate (POM) and Ag clusters is reported, where two types of clusters align alternatively along the nanowire. Low symmetrical POM clusters of [P2 W17 O61 ]10- , [P2 W15 O56 ]12- , and [EuW10 O36 ]9- can be used as building blocks. The directly bonding cluster units result in interactive electronic structures of Ag and POM clusters, as well as the greatly promoted electron transfer during the redox reaction. The Ag-P2 W17 nanowires perform significantly enhanced activities in both electrochemical sensing and catalytic gasoline desulfurization compared with individual building blocks, demonstrating the extraordinary application properties and promising potentials of cluster-based heteroconstructions.

Cluster-Nuclei Coassembled One-Dimensional Subnanometer Heteronanostructures.

The cluster-nuclei coassembled strategy provides an impressive way to obtain 1D subnanometer heteronanostructures, including subnanometer nanowires and subnanometer nanobelts. These nanomaterials have diameters and thicknesses close to the size of a unit cell and exhibit excellent performance originating from multicomponent synergy. This Mini Review summarizes the recent progress of these novel functional nanomaterials, including their properties and applications in catalysis, energy conversion, and other fields. On the basis of previous studies, the development direction of cluster-nuclei coassembled 1D subnanometer materials is pointed out.