Gallium antimonide (GaSb)-based nanostructures have been reported via various vapor-phase synthetic routes while there is not a report on the growth of GaSb nanostructures via a complete one-step solution-phase synthetic strategy. Herein we report the design and synthesis of tadpole-like Ga/GaSb nanostructures by a one-step solution-phase synthetic route typically from the precursors of commercial triphenyl antimony (Sb(Ph)₃) and trimethylaminogallium (Ga(NMe₂)₃) at 260 °C in 1-octadecene. The GaSb nanocrystals are grown based on a solution–liquid–solid (SLS) mechanism with zinc blende phase, and their size and shape can be controlled in the procedures via manipulating the reaction conditions. Meanwhile, the tadpole-like Ga/GaSb nanostructures can be applied for the fabrication of a GaSb/Si nanostructured heterojunction-like photodetector over silicon wafer, which demonstrates excellent photoresponse and detection performances from wavelength of 405 to 1,064 nm with high photoresponding rate. Typically, the photodetector exhibits a high responsivity of 18.9 A·W⁻¹, a superior detectivity of 1.1 × 10¹³ Jones, and an ultrafast response speed of 44 ns. The present work provides a new strategy to group III–V antimonide-based semiconducting nanostructures that are capable for the fabrication of photodetector with broadband, high-detectivity, and high-speed photodetecting performances.

The incorporation of pro-osteogenic growth factors into bone graft materials to enhance bone regeneration is a key research area within the field of bone tissue engineering and regenerative medicine. However, growth factors directly incorporated in protein form are easily degraded, and have a limited active half-life, which cannot exert long-term and stable osteoinductive and oteoconductive effects. The combination of gene therapy and tissue engineering through gene-activated matrix (GAM) may provide a good alternative solution to overcome such limitations. Scaffold materials can be combined together with plasmid DNA and a chemical-based transfection agent to form GAM, through which transfected cells could secrete growth factors in a sustained manner over a longer time duration; thereby enabling bone graft materials to act as a repository of therapeutic genes, while providing structural support and a scaffold matrix for new bone tissue ingrowth. In this study, we prepared hydroxyapatite/chitosan-microspheres (HA/CS-MS) with microfabrication technology and emulsification method, and loaded the polyethylene imine/bone morphogenetic protein 2 plasmid (PEI/pBMP2) complexes with high transfection capacity (transfection efficiency up to 54.79% ± 4.95%), thus forming a novel GAM system with superior bone regeneration capacity—PEI/pBMP2-HA/CS-MS. The in vitro experiments in this study demonstrated that our GAM had excellent biocompatibility (with cell viability over 95%), and that the as-fabricated microsphere material possessed a nano-network fibrous structure similar to natural extracellular matrix (ECM), together with a higher surface area that can provide more cell adhesion sites. The sizes of the prepared microspheres were mainly distributed in the 160–180 μm range, while the maximal loading rate of PEI-pBMP2 complexes was 59.79% ± 1.85%. As a loaded complexes system, the GAM can release plasmids in a slow controlled manner, effectively transfecting surrounding target cells (release effect for up to 21 days), while cells adherent to the material can also take up plasmids, resulting in sustained secretion of the target protein, thereby effectively promoting bone regeneration. In vivo data from micro-computed tomography (micro-CT) and histological staining showed that the use of the composite materials effectively enhanced bone regeneration in defect areas. These findings thus demonstrated that the novel GAM system had excellent osteoinductivity with significant clinical potential.

Broadband optoelectronic devices intrigue enormous interests on account of their promising potential in optical communications, sensors and environmental monitoring. PbSe nanocrystals are promising candidates for the construction of next-generation photodetectors due to their fascinating intrinsic properties and solution-processed compatibility with varied substrates. Here, we report the fabrication of a broadband photodetector on the basis of high-quality solution-processed PbSe nanorods in rock-salt phase grown along unconventionally anisotropic growth direction of < 112 > zone axis. The rock-salt PbSe nanorods are synthesized in solution phase over the catalysis of Ag₂Se with relatively high-temperature body-centered cubic phase via a solution-solid-solid growth regime using oleylamine and oleic acid as solvents and stabilizer surfactants, from which the PbSe nanorods with the unconventionally anisotropic growth direction are controllably grown in size and shape in the synthetic procedure typically with about 17 nm in diameter and 58 nm in length on average. Meanwhile, the PbSe nanorods-based photodetector exhibits a broadband response from 405 to 1, 064 nm with a high responsivity of 0.78 A·W⁻¹ and a fast response time of 17.5 µs. The response time is much faster in comparison with most of the PbSe-based photodetectors with response time in millisecond level.

Intelligent gas sensors based on the layered transition metal dichalcogenides (TMDs) have attracted great interest in the field of gas sensing due to their multiple active sites, fast electron, mass transfer capability and large surface-to-volume ratio. However, conventional TMDs-based sensors typically work at elevated temperature in inert atmosphere, which would largely limit the corresponding practical applications. Herein, novel oxygen-doped MoSe₂ hierarchical nanostructures composed of ultrathin nanosheets with large specific surface area have been designed and generated typically at 200 °C in air for fast and facile gas sensing of trimethylamine (TMA), effectively. Benefited from the gas-accessible hierarchical morphology and high surface area with abundant nanochannels, highly sensitive and selective detection of trace TMA has been achieved under ambient condition, and as detected the theoretical limit of detection (LOD) is 8 ppb, which is the lowest for TMA detection under ambient condition among the reported studies. The mechanism of oxygen doping on the improved gas-sensing performance has been investigated, revealing that the oxygen doping could greatly optimize the electronic structure, thus regulate the Fermi level of MoSe₂ as well as the affinity between TMA molecule and sensor surface. It is expected that the oxygen doping strategy developed for the highly efficient gas sensors based on TMDs in present work may also be applicable to other types of gas-sensing semiconductors, which could open up a new direction for the rational design of high-performance gas sensors working under ambient condition.

Advances in the photocurrent conversion of two-dimensional (2D) transition metal dichalcogenides have enabled the realization and application of ultrasensitive and broad-spectral photodetectors. The requirements of previous devices constantly drive for complex technological implementation, resulting in limits in scale and complexity. Furthermore, the development of large-area and low-cost photodetectors would be beneficial for applications. Therefore, we demonstrate a novel design of a heterojunction photodetector based on solution-processed ultrathin MoSe2 nanosheets to satisfy the requirements of its application. The photodetector exhibits a high sensitivity to visible–near infrared light, with a linear dynamic range over 124 decibels (dB), a detectivity of ~1.2 × 10¹² Jones, and noise current approaching 0.1 pA·Hz^–1/2 at zero bias. Significantly, the device shows an ultra-high response speed up to 30 ns with a 3-dB predicted bandwidth over 32 MHz, which is far better than that of most of the 2D nanostructured and solution-processable photodetectors reported thus far and is comparable to that of commercial Si photodetectors. Combining our results with material-preparation methods, together with the methodology of device fabrication presented herein, can provide a pathway for the large-area integration of low-cost, high-speed photodetectors.

A new protocol for the synthesis of nearly monodisperse gold nanoparticles with controllable size is described. The pathway is based on the reduction of AuCl₄^– by ammonium bicarbonate in the presence of sodium stearate under hydrothermal conditions. The particle sizes could be easily tuned by regulating the reaction conditions including precursor concentration, reaction temperature and growth time. A tentative explanation for the reduction and growth mechanism of uniform gold nanoparticles has been proposed. The as-prepared gold particles showed good catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol by excess NaBH₄, and a surface-enhanced Raman scattering (SERS) study suggested that the gold nanoparticles exhibited a high SERS effect on the probe molecule Rhodamine 6G.

We report the synthesis of one-dimensional (1-D) magnetic Fe₂P nanowires and Fe₂P@C core@shell nanocables by the reactions of triphenylphosphine (PPh₃) with Fe powder (particles) and ferrocene (Fe(C₅H₅)₂), respectively, in vacuum-sealed ampoules at 380–400 ℃. The synthesis is based on chemical conversion of micrometer or nanometer sized Fe particles into Fe₂P via the extraction of phosphorus from liquid PPh₃ at elevated temperatures. In order to control product diameters, a convenient sudden-temperature-rise strategy is employed, by means of which diameter-uniform Fe₂P@C nanocables are prepared from the molecular precursor Fe(C₅H₅)₂. In contrast, this strategy gives no obvious control over the diameters of the Fe₂P nanowires obtained using elemental Fe as iron precursor. The formation of 1-D Fe₂P nanostructures is ascribed to the cooperative effects of the kinetically induced anisotropic growth and the intrinsically anisotropic nature of hexagonal Fe₂P crystals. The resulting Fe₂P nanowires and Fe₂P@C nanocables display interesting ferromagnetic–paramagnetic transition behaviors with blocking temperatures of 230 and 268 K, respectively, significantly higher than the ferromagnetic transition temperature of bulk Fe₂P (T_C = 217 K).