Long-lifetime aqueous Si-air batteries prepared by growing multi-dimensionally tunable ZIF-8 crystals on Si anodes.

Si-air batteries have a high energy density, high theoretical voltage, and long lifetime, but they present a low anode utilization rate in a potassium hydroxide electrolyte. In this work, a ZIF-8 protective layer was prepared and modulated by a secondary growth method and then applied to protect the Si flat and Si nanowire (NW) anodes of a Si-air battery. By adjusting the conversion ratio, particle size, and crystallinity of ZIF-8 on the Si surface, the contact mode of the Si anode with water and OH- was controlled, thus achieving long-term corrosion and passivation resistance. Si NWs@ZIF-8 exhibited the highest average discharge voltage of 1.16 V, and the Si flat@ZIF-8 anode achieved the longest discharge time of 420 h. This work confirms that ZIF-8 acts as an anode protective layer to improve the properties of Si-air batteries and also provides valuable insights into the protection of Si anodes by MOFs.

A Review on Covalent Organic Frameworks as Artificial Interface Layers for Li and Zn Metal Anodes in Rechargeable Batteries.

Li and Zn metals are considered promising negative electrode materials for the next generation of rechargeable metal batteries because of their non-toxicity and high theoretical capacity. However, the uneven deposition of metal ions (Li+ , Zn2+ ) and the uncontrolled growth of dendrites result in poor electrochemical stability, unsatisfactory cycle life, and rapid capacity decay of batteries assembled with Li and Zn electrodes. Owing to the unique internal directional channels and abundant redox active sites of covalent organic frameworks (COFs), they can be used to promote uniform deposition of metal ions during stripping/electroplating through interface modification strategies, thereby inhibiting dendrite growth. COFs provide a new perspective in addressing the challenges faced by the anodes of Li metal batteries and Zn ion batteries. This article discusses the stability and types of COFs, and summarizes some novel COF synthesis methods. Additionally, it reviews the latest progress and optimization methods of using COFs for metal anodes to improve battery performance. Finally, the main challenges faced in these areas are discussed. This review will inspire future research on metal anodes in rechargeable batteries.

In/Ga-Doped Si as Anodes for Si-Air Batteries with Restrained Self-Corrosion and Surface Passivation: A First-Principles Study.

Silicon-air batteries (SABs) are attracting considerable attention owing to their high theoretical energy density and superior security. In this study, In and Ga were doped into Si electrodes to optimize the capability of Si-air batteries. Varieties of Si-In/SiO2 and Si-Ga/SiO2 atomic interfaces were built, and their properties were analyzed using density functional theory (DFT). The adsorption energies of the SiO2 passivation layer on In- and Ga-doped silicon electrodes were higher than those on pure Si electrodes. Mulliken population analysis revealed a change in the average number of charge transfers of oxygen atoms at the interface. Furthermore, the local device density of states (LDDOS) of the modified electrodes showed high strength in the interfacial region. Additionally, In and Ga as dopants introduced new energy levels in the Si/SiO2 interface according to the projected local density of states (PLDOS), thus reducing the band gap of the SiO2. Moreover, the I-V curves revealed that doping In and Ga into Si electrodes enhanced the current flow of interface devices. These findings provide a mechanistic explanation for improving the practical efficiency of silicon-air batteries through anode doping and provide insight into the design of Si-based anodes in air batteries.

Progress and Prospect of Zn Anode Modification in Aqueous Zinc-Ion Batteries: Experimental and Theoretical Aspects.

Aqueous zinc-ion batteries (AZIBs), the favorite of next-generation energy storage devices, are popular among researchers owing to their environmental friendliness, low cost, and safety. However, AZIBs still face problems of low cathode capacity, fast attenuation, slow ion migration rate, and irregular dendrite growth on anodes. In recent years, many researchers have focused on Zn anode modification to restrain dendrite growth. This review introduces the energy storage mechanism and current challenges of AZIBs, and then some modifying strategies for zinc anodes are elucidated from the perspectives of experiments and theoretical calculations. From the experimental point of view, the modification strategy is mainly to construct a dense artificial interface layer or porous framework on the anode surface, with some research teams directly using zinc alloys as anodes. On the other hand, theoretical research is mainly based on adsorption energy, differential charge density, and molecular dynamics. Finally, this paper summarizes the research progress on AZIBs and puts forward some prospects.

An n-Type All-Fused-Ring Molecule with Photoresponse to 1000 nm for Highly Sensitive Near-Infrared Photodetector.

Most of all-fused-ring π-conjugated molecules have wide or medium bandgap and show photo response in the visible range. In this work, an all-fused-ring n-type molecule, which exhibits an ultrasmall optical bandgap of 1.22 eV and strong near-infrared (NIR) absorption with an onset absorption wavelength of 1013 nm is reported. The molecule consists of 14 aromatic rings and has electron donor-acceptor characteristics. It exhibits excellent n-type properties with low-lying HOMO/LUMO energy levels of -5.48 eV/-3.95 eV and high electron mobility of 7.0 × 10-4  cm2  V-1  s-1 . Most importantly, its thin film exhibits a low trap density of 5.55 × 1016  cm-3 because of the fixed molecular conformation and consequently low conformation disorder. As a result, organic photodetector (OPD) based on the compound exhibits a remarkably low dark current density (Jd ) of 2.01 × 10-10  A cm-2 at 0 V. The device shows a shot-noise-limited specific detectivity (Dsh *) of exceeding 1013  Jones at 400-1000 nm wavelength region with a peak specific detectivity of 4.65 × 1013  Jones at 880 nm. This performance is among the best reported for self-powered NIR OPDs.

Ge nanowires on top of a Ge substrate for applications in anodes of Li and Na ion batteries: a first-principles study.

In this study, density functional theory (DFT) was used to research the adsorption and diffusion features of Li and Na on Ge nanowires on top of a Ge substrate. The adsorption energies at different positions are 0.71-1.28 eV for Na and -2.96--2.13 eV for Li. The adsorption energies can be further reduced by surface modification with one or two P atoms. In particular, the sidewall of the Ge nanowire modified by two P atoms is most favorable to adsorb Li/Na. In addition, we used the nudged elastic band (NEB) method to study the diffusion pathways of Li/Na on the sidewall of Ge NW and the Ge substrate and computed their energy barriers. When Li or Na diffuses across the Ge NW, the energy barrier is 0.65 or 0.79 eV, indicating that the Ge NW can be applied to anodes in lithium and sodium ion batteries. Finally, the insertion of more lithium and sodium atoms into the Ge NW would cause volume expansion and the average length of Ge-Ge bonds to increase. This work will contribute to studying the adsorption and diffusion of Li and Na on nanowires with a substrate and the volume expansion caused by the insertion of Li/Na into the nanowires. Additionally, it provides guidance for designing Ge anodes for sodium ion batteries.

Rotation alignment of a camera-IMU system using a single affine correspondence.

We propose an accurate and easy-to-implement method on rotation alignment of a camera-inertial measurement unit (IMU) system using only a single affine correspondence in the minimal case. The known initial rotation angles between the camera and IMU are utilized; thus, the alignment model can be formulated as a polynomial equation system based on homography constraints by expressing the rotation matrix in a first-order approximation. By solving the equation system, we can recover the rotation alignment parameters. Furthermore, more accurate alignment results can be achieved with the joint optimization of multiple stereo image pairs. The proposed method does not require additional auxiliary equipment or a camera's particular motion. The experimental results on synthetic data and two real-world data sets demonstrate that our method is efficient and precise for the camera-IMU system's rotation alignment.

A photo-renewable ZIF-8 photo-electrochemical sensor for the sensitive detection of sulfamethoxazole antibiotic.

Electroanalysis is an effective monitoring method for organic pollution in environmental samples. However, chemical fouling with the formation of non-conductive fouled films easily occurs on the surface of the electrode during organic pollution detection that would inactivate the electrode and affect the detecting sensitivity of organic pollution. In this work, we found that zeolitic imidazolate framework-8 (ZIF-8) electrode can achieve effective degradation of non-conductive fouled films under the light illumination during electrochemical detection of some typical organic pollution (sulfamethoxazole (SMX), Bisphenol A (BPA) and diclofenac sodium (DS)). Profiting from the charge transfer capability and photoelectric characteristics, ZIF-8 electrode exhibits a lower detection limitation for organic pollution detection and superior regeneration property. The nice detection and superior regenerated property are mainly due to non-selective superoxide radical (·O2-) and hydroxyl radicals (·OH) mediation produced by ZIF-8 electrode under light illumination that can mineralize anodic fouled products and resume surface reactive sites. Compared with the single electrochemical determination, photo-assisted electroanalysis provides a stable monitoring and a renewable pathway for practical applications.

Self-calibration of cameras using affine correspondences and known relative rotation angle.

This paper proposes a flexible method for camera self-calibration using affine correspondences and known relative rotation angle, which applies to the case that camera and inertial measurement unit (IMU) are tightly fixed. An affine correspondence provides two more constraints for the self-calibration problem than a traditional point correspondence, and the relative rotation angle can be derived from the IMU. Therefore, calibrating intrinsic camera parameters needs fewer correspondences, which can reduce the iterations and improve the algorithm's robustness in the random sample consensus framework. The proposed method does not require rotational alignment between the camera and the IMU. This advantage makes our method more convenient and flexible. The experimental results of both synthetic data and publicly available real datasets demonstrate that our method is effective and accurate for camera self-calibration.

Molecular Acceptors Based on a Triarylborane Core Unit for Organic Solar Cells.

Triarylboranes that exhibit p-π* conjugation serve as versatile building blocks to design n-type organic/polymer semiconductors. A series of new molecular acceptors based on triarylborane is reported here. These molecules are designed with a boron atom that bears a bulky 2,4,6-tri-tert-butylphenyl (Mes*) substituent at the core and strong electron-withdrawing 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile (IC) units as the end-capping groups that are linked to the core by bithiophene bridges. Butyl or butoxy groups are introduced to the bithiophene units to tune the optoelectronic properties. These molecules show nearly planar backbones with highly localized steric hindrance at the core, low LUMO/HOMO energy levels, and broad absorption bands spanning the visible region, which are all very desirable characteristics for use as electron acceptors in organic solar cell (OSC) applications. The attachment of butyl groups to the bithiophene bridges brings about a slightly twisted backbone, which in turn promotes good solubility and homogeneous donor/acceptor blend morphology, whereas the introduction of butoxy groups leads to improved planarity, favorable stacking in the film state, and a greatly reduced band gap. OSC devices based on these molecules exhibit encouraging photovoltaic performances with power conversion efficiencies reaching up to 4.07 %. These results further substantiate the strong potential of triarylboranes as the core unit of small molecule acceptors for OSC applications.

Self-calibration approach to stereo cameras with radial distortion based on epipolar constraint.

In this paper, we propose a self-calibration approach to stereo cameras with radial distortion from stereo image pairs of a common 3D scene. Based on the epipolar constraint in the stereo image pair, the intrinsic and extrinsic parameters of stereo cameras are estimated synchronously with a minimum number of nine image point correspondences. It is significant within a random sample consensus (RANSAC) scheme to cope with the outliers of feature matches efficiently and robustly. Then the inliers of the stereo image pair that have been determined after RANSAC are used to optimize the calibration parameters of stereo cameras. Furthermore, more accurate calibration results can be achieved with the joint optimization of multiple stereo image pairs. Both synthetic and real data are used to evaluate the performance of the proposed method, demonstrating that our method can calibrate stereo cameras with radial distortions efficiently and accurately.

The surface passivation of Ge(100) and Ge(111) anodes in Ge-air batteries with different doping types and concentrations.

The surface passivation of Ge(100) and Ge(111) anodes in Ge-air batteries with different doping types and concentrations is analyzed by density function theory (DFT) calculations. Compared with Ge(111) anodes, the surface passivation is restrained on Ge(100) anodes as they have larger binding energies with GeO2 layers. Meanwhile, doping would hinder the formation of a GeO2 layer on Ge anodes, especially for p-type doping, like B. The dissimilarities of the electrostatic potential differences and projected local density of states between the p-type Ge(100)/GeO2 and Ge(111)/GeO2 also reveal the origins of their distinct performances in Ge-air batteries. Furthermore, the I-V curves show that the Ge(100)/GeO2/Ge(100) device has a higher current than the Ge(111)/GeO2/Ge(111) device. This work would help to fundamentally comprehend the different electrochemical properties of Ge-air batteries with different orientations and doping and provide guidelines for the design of Ge anodes in Ge-air batteries.

Removal of vanadium from vanadium-containing wastewater by amino modified municipal sludge derived ceramic.

In this work, an amino modified porous ceramic derived from municipal sludge was synthesized for the adsorption of vanadium (V) from wastewater. In this approach, a maximum vanadium (V) removal of 99.8% can be achieved by using 800 g adsorbent with a height of 800 mm when the initial concentration of vanadium (V) was 50 mg/L, pH was 4, flow rate was 5 L/h.

Pd based in situ AOPs with heterogeneous catalyst of FeMgAl layered double hydrotalcite for the degradation of bisphenol A and landfill leachate through multiple pathways.

In situ degradation of organic contaminants by Pd and electro-generated H2 and O2 overcomes the drawbacks to traditional Fenton process, and conducting heterogeneous catalyst of FeMgAl layered double hydrotalcite (LDH) further improved the efficiency and stability. Using bisphenol A (BPA) as the model contaminants, 90% removal can be achieved with 1200 mg/L Pd/Al2O3 and FeMgAl-2. The reusability was satisfying due to the very limited leaching of Fe ions at 0.1 ppm level. FeMgAl also amplified the window of pH for Pd-catalyzed in situ advanced oxidation processes (AOPs) from 3 by homogenous Fe(II) to 3-7 by FeMgAl LDH. The COD of landfill leachate effluent of the MBR system removed by about 52.3% by this system by the initial pH was 5. Characterizations revealed the distinguishing features associated with LDH structure such as large surface area, good stability, basic character, and strong linage among active sites were accounted for the remarkable performances over a wide pH window. Five reactive intermediates were observed and multiple degradation pathways were proposed in Pd-catalyzed in situ AOP for the first time. Interestingly, because of the unique role of Pd catalyst, these degradation pathways were clearly distinguished from traditional Fenton or Fenton-like AOPs and may provide a new approach of in situ heterogeneous AOPs for refractory contaminants in future.

Synergetic SERS Enhancement in a Metal-Like/Metal Double-Shell Structure for Sensitive and Stable Application.

Because of either thermal/chemical instability or high optical loss in noble metal nanostructures, searching for alternative plasmonic materials is becoming more and more urgent, considering the practical biosensing applications under various extreme conditions. In this work, titanium nitride (TiN), a low-loss metal-like material with both excellent thermal and excellent chemical stabilities, was proposed to composite with Ag hollow nanosphere (HNS) nanostructures as an effective surface-enhanced Raman scattering (SERS) substrate to realize both highly sensitive and highly stable molecular detection. Because of the multiple-mode local surface plasmon resonance around the spherical composite nanospheres and the "gap effect" derived from the ultrasmall nanogaps within the precisely controlled plasmonic arrays, an intensively enhanced local field was successfully induced on this SERS substrate. Combined with the unique charge transferring process between Ag and TiN, a synergistically enhanced SERS sensitivity involving both physical and chemical mechanisms was achieved. Especially, with the isolation of TiN, a time-durable Raman detection on these TiN-Ag HNS arrays was accomplished, showing great potential for practical applications.

Immobilization of Cd in landfill-leachate-contaminated soil with cow manure compost as soil conditioners: A laboratory study.

Introducing cow manure compost as an amendment in landfill-leachate-contaminated soils is proved to be an effective technique for the immobilization of Cd in this study. Landfill-leachate-contaminated soil was collected from an unlined landfill in China and amended with a different blending quantity of cow manure compost (0, 12, 24, 36, and 48 g per 200 g soil), which was made by mixing cow manure and chaff at a ratio of 1/1 and maturing for 6 months. pH values of five different blending quantity mixtures increased by 0.2-0.4, and the organic matter levels increased by 2.5-7%, during a remediation period of 5 weeks. Four fractions of Cd named exchangeable Cd, reducible Cd, oxidizable Cd, and residual Cd in soil were respectively analyzed by a sequential extraction procedure. Introducing the cow manure compost application resulted in more than 40% lower exchangeable Cd but a higher concentration of oxidizable Cd in soils, and mass balance results showed nearly no Cd absorption by applied material, indicating that transformation of exchangeable Cd into oxidization forms was the main mechanism of Cd immobilization when cow manure compost was used as an amendment. The Pearson correlation showed that increasing of pH values significantly improved the efficiency of Cd immobilization, with a correlation coefficiency of 0.940 (p < 0.05). This is the first attempt at heavy metal immobilization in landfill-leachate-contaminated soil by cow manure compost, and findings of this work can be integrated to guide the application. IMPLICATIONS: Addition of cow manure compost (CMC) was effective in reducing exchangeable Cd in landfill-leachate-contaminated soils (LLCS). The immobilization effect of Cd was mainly assigned to the redistribution of labile soil Cd. Organic matter (OM) and pH value increased with CMC application. The pH values were more sensitive to Cd immobilization efficiency. It was proved that CMC can be safely and effectively used for the restoration of LLCS.

High Stability Induced by the TiN/Ti Interlayer in Three-Dimensional Si/Ge Nanorod Arrays as Anode in Micro Lithium Ion Battery.

Three-dimensional (3D) Si/Ge-based micro/nano batteries are promising lab-on-chip power supply sources because of the good process compatibility with integrated circuits and Micro/Nano-Electro-Mechanical System technologies. In this work, the effective interlayer of TiN/Ti thin films were introduced to coat around the 3D Si nanorod (NR) arrays before the amorphous Ge layer deposition as anode in micro/nano lithium ion batteries, thus the superior cycling stability was realized by reason for the restriction of Si activation in this unique 3D matchlike Si/TiN/Ti/Ge NR array electrode. Moreover, the volume expansion properties after the repeated lithium-ion insertion/extraction were experimentally investigated to evidence the superior stability of this unique multilayered Si composite electrode. The demonstration of this wafer-scale, cost-effective, and Si-compatible fabrication for anodes in Li-ion micro/nano batteries provides new routes to configurate more efficient 3D energy storage systems for micro/nano smart semiconductor devices.

ZIF-8 Cooperating in TiN/Ti/Si Nanorods as Efficient Anodes in Micro-Lithium-Ion-Batteries.

Zeolite imidazolate framework-8 (ZIF-8) nanoparticles embedded in TiN/Ti/Si nanorod (NR) arrays without pyrolysis have shown increased energy storage capacity as anodes for lithium ion batteries (LIBs). A high capacity of 1650 µAh cm(-2) has been achieved in this ZIF-8 composited multilayered electrode, which is ∼100 times higher than the plain electrodes made of only silicon NR. According to the electrochemical impedance spectroscopy (EIS) and (1)H nuclear magnetic resonance (NMR) characterizations, the improved diffusion of lithium ions in ZIF-8 and boosted electron/Li(+) transfer by the ZIF-8/TiN/Ti multilayer coating are proposed to be responsible for the enhanced energy storage ability. The first-principles calculations further indicate the favorable accessibility of lithium with appropriate size to diffuse in the open pores of ZIF-8. This work broadens the application of ZIF-8 to silicon-based LIBs electrodes without the pyrolysis and provides design guidelines for other metal-organic frameworks/Si composite electrodes.

Clinical Implantation with the novel D-13 prosthesis for inguinal hernioplasty: A retrospective cohort study.

INTRODUCTION: Using a mesh to repair inguinal hernias is now a standard procedure that is widely accepted as superior to primary suture repair. Although a variety of meshes are available, individual meshes may have their own unattractive features. This retrospective study examines the efficacy of our originally designed D-13 prosthesis, which is used in patients with inguinal hernias. METHODS: A total of 305 patients who underwent a herniorrhaphy between January 2009 and March 2011 were included in this study. The recurrent rate, chronic pain and feeling of a foreign body were examined at a 3-year follow-up. The D-13 prosthesis, made from clear polypropylene monofilament mesh, was originally designed by the first author of this study and constructed with the upper and lower pieces of polypropylene mesh having different shapes and sizes. Both pieces are linked together by a connector. RESULTS: The mesh is well tolerated. At a 3-year follow-up, only two patients had a foreign body sensation at the operative site, and three patients had recurrent hernias. CONCLUSION: The unique design of the D-13 prosthesis with two pieces of mesh provided encouraging long-term outcome for hernia recurrence, chronic pain and the feeling of a foreign body.

Removal of refractory contaminants in municipal landfill leachate by hydrogen, oxygen and palladium: a novel approach of hydroxyl radical production.

Municipal solid waste (MSW) leachate contains various refractory pollutants that pose potential threats to both surface water and groundwater. This paper established a novel catalytic oxidation process for leachate treatment, in which OH is generated in situ by pumping both H2 and O2 in the presence of Pd catalyst and Fe(2+). Volatile fatty acids in the leachate were removed almost completely by aeration and/or mechanical mixing. In this approach, a maximum COD removal of 56.7% can be achieved after 4h when 200mg/L Fe(2+) and 1250mg/L Pd/Al2O3 (pH 3.0) are used as catalysts. After oxidation, the BOD/COD ratio in the proposed process increased from 0.03 to 0.25, indicating that the biodegradability of the leachate was improved. By comparing the efficiency on COD removal and economical aspect of the proposed Pd-based in-situ process with traditional Fenton, electro-Fenton and UV-Fenton for leachate treatments, the proposed Pd-based in-situ process has potential economic advantages over other advanced oxidation processes while the COD removal efficiency was maintained.