One-Dimensional Superlattice Heterostructure Library

Abstract

Axially, epitaxially organizing nano-objects of distinct compositions and structures into superlattice nanowires enables full utilization of sunlight, readily engineered band structures, and tunable geometric parameters to fit carrier transport, thus holding great promise for optoelectronics and solar-to-fuel conversion. To maximize their efficiency, the general and highprecision synthesis of colloidal axial superlattice nanowires (ASLNWs) with programmable compositions and structures is the prerequisite; however, it remains challenging. Here, we report an axial encoding methodology toward the ASLNW library with precise control over their compositions, dimensions, crystal phases, interfaces, and periodicity. Using a predesigned, editable nanoparticle framework that offers the synthetic selectivity, we are able to chemically decouple adjacent sub-objects in ASLNWs and thus craft them in a controlled approach, yielding a library of distinct ASLNWs. We integrate therein plasmonic, metallic, or near-infrared-active chalcogenides, which hold great potential in solar energy conversion. Such synthetic capability enables a performance boost in target applications, as we report order-of-magnitude enhanced photocatalytic hydrogen production rates using optimized ASLNWs compared to corresponding solo objects. Furthermore, it is expected that such unique superlattice nanowires could bring out new phenomena.

Hierarchically Periodic Macroporous CdS–ZnO Heterojunctions with Multiple Quantum Well-like Band Alignments for Efficient Photocatalytic Hydrogen Evolution without a Cocatalyst

“…However, we note that CdS is generally not a designed host. Meanwhile, the carrier utilization process is unbalanced due to the random distribution of heterojunctions on the pore walls, and the presence of numerous bare non-heterogeneous interfaces makes charge separation/transfer very limited . Moreover, many homogeneous interfaces still exist in the HPM structures prepared by this strategy, and the grain boundaries are regarded as recombination centers for photogenerated electrons and holes. , Therefore, if two photocatalysts can be alternately bridged in the form of grains as the HPM skeletons (Figure b), the carrier recombination at the homogeneous grain boundaries will be replaced by unique recombination at the Z-scheme under light illumination.…”

Sulfur Vacancy and Ti3C2Tx Cocatalyst Synergistically Boosting Interfacial Charge Transfer in 2D/2D Ti3C2Tx/ZnIn2S4 Heterostructure for Enhanced Photocatalytic Hydrogen Evolution

“…[ 1 ] Over the past decades, the emergence of novel catalytic materials from particles to nanoscale has promoted the continuous development in photocatalytic water splitting. [ 2 ] However, due to the limitations of the electronic structure, [ 3 ] morphology, [ 4 ] energy band structure, [ 5 ] and surface chemical state, [ 6 ] the development of semiconductors with excellent efficiency of photocatalytic water splitting remains a challenge. [ 7 ] In recent years, ultrathin 2D materials have become promising catalysts for photocatalytic hydrogen reaction due to their advantages of more exposed active sites [ 8 ] and shorter electron migration distance.…”

Catalyzed Growth for Atomic-Precision Colloidal Chalcogenide Nanowires and Heterostructures: Progress and Perspective

“…Starting from the well-defined CdS-ZnS QDNWs grown via the pulsed axial epitaxy strategy, a library of ASLNWs with high-level control over compositions, sizes, crystal phases, interfaces, and periodicity can now be attainable. The key is to implement an axial encoding methodology that allows regulating reaction chemoselectivity . In practice, CdS-ZnS ASLNWs with controllable diameter, spacing, number, and periodicity of CdS QDs serve as predesigned, reconfigurable nanoscale frameworks for subsequent regioselective chemical transformations.…”

“…(e, f) Benifiting from their superior light absorption range and charge-separation efficiency (e), Cu 1.8 S-ZnS ASLNWs as a proof of concept present significantly enhanced photocatalytic performances as compared to solo counterparts (f). Reproduced from ref . Copyright 2021 American Chemical Society.…”

“…The key is to implement an axial encoding methodology that allows regulating reaction chemoselectivity. 66 In practice, CdS-ZnS ASLNWs with controllable diameter, spacing, number, and periodicity of CdS QDs serve as predesigned, reconfigurable nanoscale frameworks for subsequent regioselective chemical transformations. By manipulating the reaction thermodynamics and kinetics, one is able to chemically decouple the adjacent segments in nanowires and selectively convert CdS subunits into the P-type, nearinfrared active Cu 1.8 S and Ag 2 S subunits, resulting in Cu 1.8 S-ZnS and Ag 2 S-ZnS ASLNWs (Figure 4a,b).…”