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Liquid-phase exfoliation (LPE) of emergent materials composed of weakly bound one-dimensional (1D) and quasi-1D (q-1D) building blocks presents a straightforward route not only for the discovery of confined physical states in 1D but also for the realization of scalable functional devices. However, compared to the more established routes in two-dimensional (2D) crystals, the nature of LPE in 1D and q-1D crystals presents a more random process. This distinction arises from the various available interchain directions across several crystallographic facets unique to 1D and q1D solids, from which the chains can be cleaved apart into a stochastic combination of nanowires, nanoribbons, and nanosheets. Using the 1D ionic phase comprised of ∼4.3 Å thin chains, (NbSe4)3I, we demonstrate herein the profound influence of crystal morphology, exposed facets, and their degree of wettability, passivation, and surface roughness in directing the LPE behavior of 1D crystals. Through the growth of bulk crystals as long needles with exposed (hk0) facets or as quasi-2D flakes with exposed (00l) facets susceptible to passivation, we show that these two distinct precursor morphologies display divergent behaviorboth in solvent preference and quality of resulting nanostructures. Under optimal conditions involving bulk needles and tetrahydrofuran as solvent, we show that the LPE of (NbSe4)3I results in ultrathin nanoribbons with high aspect ratios bearing lengths >5 μm, thicknesses down to 7.2 ± 2.6 nm, and widths of 26.4 ± 10.9 nm. The nanoribbons, solution processable as thin films, retain their native crystal structure and semiconducting character. Moreover, the nanoribbons also manifest pronounced degrees of bending and substrate-driven twisting at the nanoscale while maintaining long-range order. These results highlight a means to understand the fundamental chemical and physical behavior of noncovalently bound 1D solids through the realization of solution-processable 1D nanoribbons and nanowires that also have the potential as components for next-generation devices that approach the atomic scale. 

The rediscovery of one-dimensional (1D) and quasi-1D (q-1D) van der Waals (vdW) crystals ushered the realization of nascent physical properties in 1D that are suitable for applications in photonics, electronics, and sensing. However, despite renewed interest in the creation and understanding of the physical properties of 1D and q-1D vdW crystals, the lack of accessible synthetic pathways for growing well-defined nanostructures that extend across several length scales remains. Using the highly anisotropic 1D vdW NbS3–I crystal as a model phase, we present a catalyst-free and bottom-up synthetic approach to access ultralong nanowires, with lengths reaching up to 7.9 mm and with uniform thicknesses ranging from 13 to 160 nm between individual nanowires. Control over the synthetic parameters enabled the modulation of intra- and interchain growth modalities to selectively yield only 1D nanowires or quasi-2D nanoribbons. Comparative synthetic and density functional theory (DFT) studies with a closely related nondimerized phase, ZrS3, show that the unusual preferential growth along 1D can be correlated to the strongly anisotropic bonding and dimeric nature of NbS3–I. 

The recent rediscovery of 1D and quasi-1D (q-1D) van der Waals (vdW) crystals has laid foundation for the realization of emergent electronic, optical, and quantum-confined physical phenomena in both bulk and at the nanoscale. Of these, the highly anisotropic q-1D vdW crystal structure and the visible-light optical/ optoelectronic properties of antimony trisulfide (Sb2S3) have led to its widespread consideration as a promising building block for photovoltaic and non-volatile phase change devices. However, while these applications will greatly benefit from well-defined and sub-nanometer-thick q-1D structures, little has been known about feasible synthetic routes that can access single covalent chains of Sb2S3. In this work, we explore how encapsulation in single or multi-walled carbon nanotubes (SWCNTs or MWCNTs) and visible-range transparent boron nitride nanotubes (BNNTs) influences the growth and phase of Sb2S3 nanostructures. We demonstrate that nanotubes with smaller diameters had a more pronounced effect in the crystallographic growth direction and orientation of Sb2S3 nanostructures, promoting the crystallization of the guest structures along the long-axis [010]-direction. As such, we were able to reliably access wellordered few to single covalent chains of Sb2S3 when synthesized within defect-free SWCNTs with sub2 nm inner diameters. Intriguingly, we found that the degree of crystalline order of Sb2S3 nanostructures was strongly influenced by the presence of defects and discontinuities along the Sb2S3-nanotube interface. We show that amorphous nanowire domains of Sb2S3 form around defect sites in larger, multi-walled nanotubes that manifest inner wall defects and discontinuities, suggesting a means to manipulate the crystallization dynamics of confined sub-10 nm-thick Sb2S3 nanostructures within nanotubes. Lastly, we show that ultranarrow amorphous Sb2S3 can impart functionality onto isolable BNNTs with photocurrent generation in the pA range which, alongside the dispersibility of the Sb2S3@BNNTs, could be leveraged to easily fabricate photoresistors only a few nm in width. Altogether, our results serve to solidify the understanding of how q-1D vdW pnictogen chalcogenides crystallize within confined synthetic platforms and are a step towards realizing functional materials from ensembles of encapsulated heterostructures 

Charge and energy transport within living systems are fundamental processes that enable the autonomous function of excitable cells and tissues. To date, localized control of these transport processes has been enabled by genetic modification approaches to render light sensitivity to cells. Here, we present peptidic nanoassemblies as constituents of a cardiac biomaterial platform that leverages complementary sequence interactions to direct photoinduced energy transport at the cellular interface. Photophysical characterizations and conductivity measurements confirm the occurrence of energy/charge transfer and photocurrent generation upon optical excitation in both dry and electrolytic environments. Comparing an electrostatic sequence pair against a sequence-matched donor–acceptor coassembly, we demonstrate that the sequence design with charge complementarity shows more prominent photocurrent behavior. With the flanking bioadhesive units, the primary and stem cell–derived cardiomyocytes interfaced with covalently stabilized films of the optoelectronic nanostructures exhibited material-stimulated genotypic, structural, or functional cardiac features. Collectively, our findings introduce an optoelectronic cardiac biomaterial where coassembled peptide nanostructures are molecularly designed to induce light sensitivity in excitable cells without gene modification, influencing in vitro cardiac contractile behavior and expression of cardiac markers. 

Physical states in nanoscale solids are tied to their crystalline order, morphology, and size. However, deterministically accessing different nanocrystal morphologies from a single phase usually involves complex synthetic routes, catalysts, or multi-step lithographic techniques. Here, we demonstrate the catalyst-free synthesis of nanosheets and nanowires based on the luminescent 2D van der Waals (vdW) phase, GaTe, as a model phase that manifests atomic precision and a highly anisotropic quasi-1D substructure. We program the size and morphology of the resulting nanostructures by varying the relative rates of precursor deposition and diffusion, achieving dense, uniform, and widespread growth. Ultrathin nanowires resulting from this synthesis exhibit strikingly enhanced low-temperature luminescence with narrow near-infrared (NIR) emission bandwidths. These spectral characteristics arise from defect-bound states confined within a nanowire morphology that acts as a deep sub-wavelength optical cavity, making them suitable as optical emitters with small footprints either as stand-alone structures or coupled with other vdW crystals.