The combination of magnetism and upconversion luminescent property into one single nanostructure is fascinating for biological fields, such as multimodal bioimaging, targeted drug delivery, and ...imaging-guided therapy. In this review, we will provide the state-of-the-art advances on magnetic upconversion nanocomposites towards their bioapplications. Their structure design, synthesis methods, surface engineering and applications in bioimaging, drug delivery, therapy as well as biodetection will be covered.
Electrochemical atomic force microscopy (EC-AFM), a branch of a scanning probe microscopy (SPM), can image substrate topography with high resolution. Since its inception, it was extended to a wide ...range of research areas through continuous improvement. The presence of an electrolytic cell and a potentiostat makes it possible to observe the topographical changes of the sample surface in real time. EC-AFM is used in in situ corrosion research because the samples are not required to be electrically conductive. It is widely used in passive film properties, surface dissolution, early-stage corrosion initiation, inhibitor efficiency, and many other branches of corrosion science. This review provides the research progress of EC-AFM and summarizes the extensive applications and investigations using EC-AFM in corrosion science.
In this work, V-doped TiO(2) nanofibers with different V contents have been fabricated by an electrospinning technique. The as-prepared nanofibers were characterized by scanning electron microscopy ...(SEM), X-ray diffraction (XRD), Raman spectra, X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance (DR) spectroscopy. The results indicated that the V(4+) or V(5+) ions were successfully incorporated into the crystal lattice of anatase TiO(2) nanofibers. Meanwhile, the V doping could extend the visible light absorption of TiO(2) nanofibers. The photocatalytic experiments indicated that the obtained V-doped TiO(2) nanofibers possessed high activity for the photodegradation of organic pollutant methylene blue (MB). Especially, the 1.0 and 5.0 wt.% V-doped TiO(2) nanofibers exhibited the best catalytic activity under visible and ultraviolet (UV) light irradiation, respectively. Also, these nanofibers could be easily recycled without a decrease of the photocatalytic activity.
Polyaniline (PANI) particles were immobilized on electrospun polyacrylonitrile (PAN) nanofibers (NFs) to form PAN@PANI NFs via in situ polymerization at room temperature. Then, ZnO was deposited on ...the surface of PAN@PANI NFs by atomic layer deposition (ALD) to form PAN@PANI@ZnO NFs. The PANI and ZnO contents were well controlled by adjusting the polymerization time and the number of ALD cycles, respectively. The obtained PAN@PANI@ZnO NFs exhibited higher photocatalytic activity for the degradation of methylene blue under ultraviolet light irradiation than PAN@PANI and PAN@ZnO NFs, and the first-order degradation rate constant (kapp) of PAN@PANI@ZnO NFs formed with 400 ALD cycles was greater than that of PAN@ZnO NFs formed with 400 ALD cycles by a factor of 2.1. The enhanced photocatalytic activity is shown to originate from the improved charge separation of photogenerated electrons and holes due to the formation of ZnO/PANI heterojunctions in PAN@PANI@ZnO NFs. The obtained PAN@PANI@ZnO photocatalysts are easily recycled with little decrease in photocatalytic activity because of their macroscopic mat structure and flexibility.
Polyaniline (PANI) particles were immobilized on electrospun polyacrylonitrile (PAN) nanofibers (NFs) to form PAN@PANI NFs via in-situ polymerization at room temperature. After that, ZnO was deposited on the surface of PAN@PANI NFs by atomic layer deposition to form PAN@PANI@ZnO NFs. This novel ternary composite photocatalyst (PAN@PANI@ZnO NFs) displayed an enhanced photocatalytic activity for decomposing methylene blue under UV light, which was attributed to the improved charge separation of photogenerated electrons by ZnO/PANI heterojunction in photocatalytic reaction. Display omitted
•ZnO/PANI heterojunction were uniformly immobilized on electrospun PAN nanofibers.•PAN@PANI@ZnO nanofibers exhibited enhanced photocatalytic activities under UV light.•The composite nanofibers could be easily recycled due to the mats structure and flexibility.
Copper foams reinforced by embedded Carbon nanotubes (CNTs) with uniform dispersion were prepared through composite electrodeposition on melamine foam templates. The microstructure, compression ...performance and electromagnetic shielding properties were characterized or tested by XRD, Raman, SEM, tensile tester and vector network instrument, respectively. The results showed significant improvements of the compressive strength, energy absorption and electromagnetic shielding properties of the composite foams with CNTs reinforcements, as compared to the copper foam counterparts. Such composite foams are potential light-weighted materials for shock resistance and electromagnetic shielding.
•The CNTs are embedded in copper foams with uniform dispersion through electrodeposition on melamine foams.•The compressive strength and energy absorption ability of the CNTs/Cu foams are significantly improved.•The electromagnetic shielding properties of the CNTs/Cu foams are significantly improved.
At present, the direct experimental observation and confirmation of thermal damage on semiconductors remain unexplored. This report presents clear evidence of the thermal irradiation damage on the ...electrode contact region of an organic semiconductor in the electrode deposition process by applying an ultralong uniform rubrene single crystal to simultaneously fabricate vacuum-deposited electrode and stamped electrode top-contact organic field-effect transistors (OFETs). The surface potential measurements combined with the transfer characteristics show that the thermal irradiation damage causes the HOMO level of rubrene shift downwards by 0.17 eV, resulting in the enhanced contact resistance and hence the lowered field-effect mobility. This interesting experimental discovery clarifies the nature of vacuum-deposited electrode induced thermal irradiation damage on OFETs, will enhance the understanding and development of contact engineering to further improve the performance of organic electronics.
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•The thermal irradiation damage on the semiconductor is experimentally confirmed for the first time.•The stamped electrode fabrication method can completely avoid thermal irradiation on the semiconductor surface.•The stamped-electrode devices exhibit obviously higher performance than deposited-electrode devices.•The thermal irradiation enhances the charge injection barrier at the electrode/semiconductor contact interface.•The thermal irradiation increases the density of structure defects and charge traps of the rubrene single crystal.
We describe a route to synthesize In2S3/CNFs/Au ternary synergetic system with high efficiency visible-light photocatalytic activity.
•Synthesis of In2S3/CNFs/Au ternary synergetic system.•Enhanced ...visible-light photocatalytic activity.•Easy photocatalyst separation and reuse.
In this paper, carbon nanofibers (CNFs) were successfully synthesized by electrospinning technique. Next, Au nanoparticles (NPs) were assembled on the electrospun CNFs through in situ reduction method. By using the obtained Au NPs modified CNFs (CNFs/Au) as hard template, the In2S3/CNFs/Au composites were synthesized through hydrothermal technique. The results showed that the super long one-dimensional (1D) CNFs (about 306nm in average diameter) were well connected to form a nanofibrous network; and, the Au NPs with 18nm in average diameter and In2S3 nanosheets with 5–10nm in thickness were uniformly grown onto the surface of CNFs. Photocatalytic studies revealed that the In2S3/CNFs/Au composites exhibited highest visible-light photocatalytic activities for the degradation of Rhodamine B (RB) compared with pure In2S3 and In2S3/CNFs. The enhanced photocatalytic activity might arise from the high separation efficiency of photogenerated electron–hole pairs based on the positive synergetic effect between In2S3, CNFs and Au components in this ternary photocatalytic system. Meanwhile, the In2S3/CNFs/Au composites with hierarchical structure possess a strong adsorption ability towards organic dyes, which also contributed to the enhancement of photocatalytic activity. Moreover, the In2S3/CNFs/Au composites could be recycled easily by sedimentation due to their nanofibrous network structure.
Electronic devices with biomaterials have paved a way toward “green electronics” to create a sustainable future. Memristors are drawing growing attention with integrated sensing, memory, and ...computing for future artificial intelligence applications. Biomaterial is an emerging class of memristive materials (the device is called as biomemristor) for transient and/or biodegradable purpose. Importantly, several unique features such as faithful synaptic behaviors, bimodal switching, and biovoltage operations are observed in biomemristors. Moreover, the biomemristors are suitable for human‐related applications due to the inherent biocompatibility of biomaterials and flexibility of the device with ultrathin thickness. These features make the biomemristors promising for biorealistic neuromorphic applications. Herein, the state of the art of biomemristors are comprehensively summarized and systematically discussed with particular attention on their unique biorealistic features. Challenges and prospects toward the further development of biomemristors are also provided and discussed.
As emerging memristive materials, biomaterials hold great promise for “green” electronics to create a sustainable future with unique biodegradable and biocompatible properties. This review systematically outlines the state‐of‐the‐art development of biomemristor devices with a focus on their unique features for biorealistic neuromorphic applications. Future key challenges and opportunities are suggested.
The absence of an effective approach to achieve free‐standing inorganic memristors seriously hinders the development of transferable artificial synapses. Here, a transferable WOx‐based memristive ...synapse is demonstrated using a nondestructive water‐dissolution method in which the NaCl substrate is selected as the sacrificial layer due to its thermotolerance and water‐solubility. The essential synaptic learning functions are achieved to comprehensively mimic the biological synapse, such as short‐term/long‐term plasticity, paired‐pulse facilitation, and spike‐timing‐dependent plasticity. This artificial synapse can be transferred and conformed onto various unconventional substrates to manifest the flexibility, 3D conformality, and biocompatibility. There is no mechanical damage during the transfer process, and all these transferred devices present excellent synaptic emulations. The memristive behavior shows no degeneration after large‐angle bending or 100 times bending tests. This result may pave a feasible way for the realization of wearable neuromorphic computing systems in the future.
Using a nondestructive water‐dissolution method, a transferable WOX memristor is demonstrated when selecting NaCl substrate as the sacrificial layer. The synaptic devices are transferred onto diverse substrates, presenting excellent flexibility and high mechanical endurance. The essential functions of synaptic plasticity are obtained in the device on the bent state. The work offers a feasible method to enable inorganic memristors for transferable applications.
One-dimensional In2S3/TiO2 hierarchical heterostructures were fabricated based on TiO2 nanofibers by combining the electrospinning technique (for TiO2 nanofibers) with the hydrothermal method (for ...In2S3 nanosheets), which exhibited a high visible light photocatalytic activity for degradation of Methyl orange and reduction of Cr(VI) under visible light illumination (λ>420nm).
•Synthesis of one-dimensional In2S3/TiO2 hierarchical heterostructures.•Enhanced visible-light photocatalytic activity.•The mechanisms of photodegradation of MO and photoreduction of Cr(VI).
In2S3 nanosheets were assembled on electrospun TiO2 nanofibers template by a hydrothermal technique. For the obtained one-dimensional In2S3/TiO2 hierarchical heterostructures (1D In2S3/TiO2 H-HSs), the density and size of the secondary In2S3 nanosheets could be controlled by adjusting the reactant concentrations for the preparation of In2S3 in the hydrothermal process. The 1D In2S3/TiO2 H-HSs exhibited higher visible-light photocatalytic activity for the degradation of Methyl orange (MO) and the reduction of Cr(VI), as compared with the pure TiO2 nanofibers and pure In2S3 nanosheets. The enhanced visible light photocatalytic activity might be attributed to the extended absorption in the visible light region from the narrow band-gap In2S3, the effective photogenerated electron–hole separation by the photosynergistic effects of the In2S3/TiO2 H-HSs and quick electron-transfer in the 1D TiO2 nanofibers. Meanwhile, the 1D In2S3/TiO2 H-HSs could be recycled easily by sedimentation due to their nanofibrous nonwoven web structure. Moreover, the mechanisms of photodegradation of MO and photoreduction of Cr(VI) were proposed through systematical investigations. This work provided new insights into utilizing 1D In2S3/TiO2 H-HSs as high efficiency visible-light-driven photocatalysts for environmental remediation and energy conversion.
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