Lizhi Liu

Growth of ZnO hexagonal nanoprisms

We show the success of large-scale growth of ZnO hexagonal nanoprisms on silicon substrates by a two-staged mechanism. In the first stage, the catalyst nanoparticles assisted the nucleation via the vapour–liquid–solid (VLS) mechanism to form polyhedral nanoparticles. In the second stage, the nanoprism was grown up by anisotropic homoepitaxy, layer by layer, on the c-face of the polyhedral nanoparticle. The surface of the nanoprism consists of the ultraflat {0001} and planes. The nanoprism is 200–500 nm in width and controllably sized in length, of high crystalline quality and excellent optical quality. This nanoprism would be an interesting building block for highly efficient nanolasers.

H2-assisted control growth of Si nanowires

Large-scale desired silicon nanowires without amorphous silicon oxide sheath have been synthesized by thermal chemical vapor deposition using SiH4 gas at 650degreesC in a flow mixture of H-2 and N-2, compared with the short and thick Si nanowires with amorphous SiOx coating obtained in N-2. Scanning electron microscopy (SEM), Energy dispersive X-ray spectrometry (EDX) analysis, and high-resolution transmission electron microscopy (HRTEM) have been employed to characterize the Si nanowires. The effects of H-2 gas on the catalytic particle size and on the formation of Si nanowires are discussed in detail. Photoluminescence (PL) characteristics further demonstrate the large differences between the H-2-assisted grown Si nanowires and the Si nanowires grown in N-2

Two-bit ferroelectric field-effect transistor memories assembled on individual nanotubes

Carbon nanotube (CNT) ferroelectric field-effect transistors (FeFETs) with well-defined memory switch behaviors are promising for nonvolatile, nondestructive read-out (NDRO) memory operation and ultralow power consumption. Here, we report two-bit CNT-FeFET memories by assembling two top gates on individual nanotubes coated with ferroelectric thin films. Each bit of the nanotube transistor memory exhibits a controllable memory switching behavior induced by the reversible remnant polarization of the ferroelectric films, and its NDRO operation is demonstrated. The low driving voltage of 2 V, high carrier mobility over 1000 cm2 V(-1) s(-1), and potential ultrahigh integration density over 200 Gbit inch(-2) of the two-bit FeFET memory are highlighted in this paper.

Au Promoted Nickel–Iron Layered Double Hydroxide Nanoarrays: A Modular Catalyst Enabling High-Performance Oxygen Evolution

Oxygen evolution reaction (OER) plays a key role in various energy conversion and storage technologies, such as water electrolysis, regenerative fuel cells, and rechargeable metal-air batteries. However, the slow kinetics of OER limit the performance and commercialization of such devices. Herein, we report on NiFe LDH@Au hybrid nanoarrays on Ni foam for much enhanced OER. By hybridization of electronegative Au and NiFe LDH with intrinsic remarkable OER catalytic activity, this modular electrode could drive an overall ultrahigh-performance and robust OER in base with the demand of overpotentials of only 221, 235, and 270 mV to afford 50, 100, and 500 mA cm-2, respectively. Also, it exhibits superior catalytic activity and durability toward OER in 30 wt % KOH.

Antibiotic-loaded MoS2 nanosheets to combat bacterial resistance via biofilm inhibition

The emergence of antibiotic resistance has resulted in increasing difficulty in treating clinical infections associated with biofilm formation, one of the key processes in turn contributing to enhanced antibiotic resistance. With the rapid development of nanotechnology, a new way to overcome antibiotic resistance has opened up. Based on the many and diverse properties of MoS2 nanosheets that have attracted wide attention, in particular their antibacterial potential, herein, a novel antimicrobial agent to combat resistant gram-positive Staphylococcus aureus and gram-negative Salmonella was prepared using chitosan functionalized MoS2 nanosheets loading tetracycline hydrochloride drugs (abbreviated to CM-TH). The antibacterial and anti-biofilm activities of the CM-TH nanocomposites showed the synergetic effect that the combination of nanomaterials and antibiotics was more efficient than either working alone. In particularly, the minimum inhibitory concentration values generally decreased by a factor of dozens, suggesting that CM-TH may become a possible alternative to traditional antibiotics in disrupting biofilms and overcoming antibiotic resistance in treating medical diseases.The emergence of antibiotic resistance has resulted in an increasing difficulty treating clinical infections associated with biofilms formation, one of the key processes contributed to enhance antibiotic resistance in return. With the rapid development of nanotechnology, a new way to overcome antibiotic resistance was opened up. Based on multiple properties especially antibacterial potential of MoS2 nanosheets that have aroused wide attention, herein, a novel antimicrobial agent to combat resistant gram-positive Staphylococcus aureus (S. aureus) and gram-negative Salmonella was prepared using chitosan functionalized MoS2 nanosheets loading tetracycline hydrochloride drugs (abbreviated to CM-TH). The antibacterial and anti-biofilm activities of CM-TH nanocomposites expressed a synergy effect that the combination of nanomaterials and antibiotics were more efficient than both alone did. Particularly, the MIC values were generally decreased by a factor of dozens, suggesting CM-TH may become a possible alternative to traditional antibiotics in disrupting the biofilms and further to overcome antibiotic resistance in treating medical diseases.

From lamellar to hierarchical: overcoming the diffusion barriers of sulfide-intercalated layered double hydroxides for highly efficient water treatment

Herein, we focus on the design and geometry diversities of two dimensional LDHs nanosheet building blocks from lamellar to hierarchical structures to understand mass transfer mechanisms and highlight the importance of geometry-induced effects to overcome the diffusion constraints in solid–liquid interfaces.

Bacterial capture efficiency in fluid bloodstream improved by bendable nanowires

Bacterial infectious diseases, such as sepsis, can lead to impaired function in the lungs, kidneys, and other vital organs. Although established technologies have been designed for the extracorporeal removal of bacteria, a high flow velocity of the true bloodstream might result in low capture efficiency and prevent the realization of their full clinical potential. Here, we develop a dialyzer made by three-dimensional carbon foam pre-grafted with nanowires to isolate bacteria from unprocessed blood. The tip region of polycrystalline nanowires is bent readily to form three-dimensional nanoclaws when dragged by the molecular force of ligand-receptor, because of a decreasing Young’s moduli from the bottom to the tip. The bacterial capture efficiency was improved from ~10% on carbon foam and ~40% on unbendable single-crystalline nanowires/carbon foam to 97% on bendable polycrystalline nanowires/carbon foam in a fluid bloodstream of 10 cm s−1 velocity.Bacteria and other pathogens entering the blood stream can have serious consequences, which can even lead to death. Here, the authors developed a sieve containing nano-sized claws that capture and hold these intruders, thus aiding their removal from patient’s blood