Recent advancement of inorganic dissolvable electronics nucleates around a realization that single-crystal silicon nanomembrane undergoes hydrolysis in biologically relevant conditions. The silicon-based high-performance dissolvable electronic devices are initially conceived for biomedical implants that function for a programmed timeframe followed by a complete dissolution to eliminate the need for recollection. The technology developed for biomedicine also presents unique opportunities in security devices that physically destruct and in environmentally benign electronics that dissolve without a trace to reduce electronic wastes. The new class of devices with this emerging technology complements the existing efforts in organic biodegradable devices. Compatible with state-of-the-art fabrication facilities for commercial microelectronics, the technology has a huge potential for future commercialization. This mini review will first discuss the relevant materials for the inorganic dissolvable electronics and then present the demonstrated applications in functional devices, followed by a perspective for the future developments.

The aim of this study was the synthesis of hard and low-abrasive novel implant materials with built-in time-dependent antibacterial properties, which can be tailored by a well-defined time-dependent and finite release of metal ions. We were able to synthesize such smart implant surfaces employing ECR (electron cyclotron resonance)-plasma on typical titanium implant material by transforming a polymer film into diamond-like carbon (DLC) which contains metal nanoparticles as reservoirs for controlled metal ion release. We found that the amount of released antibacterial metal ions is a biexponential function of time with a high release rate during the first few hours followed by a decreased ion release rate within the following days. To describe our experimental findings, we developed a kinetic model assuming that both nanoparticles near the surface and nanoparticles in the DLC bulk contribute to the total amount of ions released with different time constants.

We demonstrate fabrication and characterization of photovoltaic (PV) devices made using pencil, paper, and commonly available economical chemicals with a power conversion efficiency of ∼1.8%. The current collecting electrode of the device composed of multilayered graphene (MuLG) was hand-drawn on the cellulosic paper using an H2B pencil. CdSe quantum dots (QD) were used for charge generation, and 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) as a bridging molecule to facilitate transfer of the photo-induced charges to the electrodes through MuLG. MuLG acted both as charge carrier and current collector electrode. The device fabrication and testing were accomplished in a wet lab under ambient conditions with minimum use of sophisticated instrumentation. The materials and devices were characterized using UV–visible, fluorescence, x-ray diffraction spectroscopy, and scanning and transmission electron microscopy. I–V characteristics of the PV devices fabricated on paper and polyester transparency substrates were performed using a solar simulator (AM 1.5) under ambient wet laboratory conditions. The use of pencil and paper makes the device fabrication simple, environmentally responsible, and accessible to layperson thus opening a new window for low cost PV and opto-electronic devices.

MnOx –CeO2/t-ZrO2 catalyst was prepared by impregnation of nanotetragonal zirconia. The NO conversion of 5 wt% MnOx –CeO2/t-ZrO2 catalyst was 68.1% at 100 °C while that of 30 wt% MnOx –CeO2/t-ZrO2 catalyst was 97.4%. The x-ray diffraction, Brunner–Emmet–Teller measurements (BET), and H2-TPR showed surface properties of the prepared catalysts were good for selective catalytic reduction reactions. X-ray photoelectron spectroscopy analysis indicated that Mn4+ and Ce4+ oxidation states were predominant on the surface of the catalyst and so was lattice oxygen which was conducive to Lewis acid sites. NH3-TPD test results demonstrated that Lewis acid sites are predominant on the surface of catalyst. The presence of SO2 reduced the catalyst activity. The realized conversion dramatically decreased to 47% from nearly 100% after 8 h. Characterization of fresh and spent catalysts indicated the deterioration of active component and deposition of NH4HSO4 or (NH4)2SO4 contribute to SO2 poisoning.

A series of Ag2S/Ag2WO4 composite microrods with different Ag2S contents (10–50 wt%) were synthesized via a facile successive precipitation route. The texture and optical properties of the pure Ag2S, Ag2WO4, and Ag2S/Ag2WO4 composites were intensively characterized by some physicochemical characterizations like N2 physical adsorption, x-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, Ultraviolet–visible spectroscopy, x‐ray photoelectron spectroscopy, photoluminescence spectroscopy, and photocurrent measurements. Under visible light irradiation, different organic dyes, e.g., methylene blue and methyl orange dye were applied to evaluate the photocatalytic performances by their photocatalytic degradation reactions. The Ag2S/Ag2WO4 composite microrods exhibited superior photocatalytic activity and stability. The high crystallinity of Ag2WO4 and improved texture properties of Ag2S/Ag2WO4 resulted in their enhanced photocatalytic property. More importantly, the Ag2S/Ag2WO4 heterojunctions with matching electronic band structures obviously enhanced the separation of photo‐generated electrons and holes, further promoting the photocatalytic reaction.

The particle size of Fe3O4 nanoparticles is controlled using a simple oxidation–precipitation method without any surfactant. The structure, morphology and physical properties of the synthesized Fe3O4 NPs were characterized using x-ray diffraction, scanning electron microscopy, transmission electron microscopy, x-ray photoelectron spectroscopy, Brunauer–Emmett–Teller, and vibrating sample magnetometer. As-prepared magnetite samples exhibited spherical morphology with average diameters of 30, 70, 250, and 600 nm, respectively. Activity of the synthesized Fe3O4 NPs was evaluated for the Fenton-like reaction, using rhodamine B (RhB) as a model molecule. The results showed that catalytic activity increases with the reduced particle size. The significant higher catalytic activity of the fine Fe3O4 NPs mainly originated from the higher specific surface area, due to the increase in exposed active site number and adsorption capacity. The reusability of 30 nm Fe3O4 NPs was also investigated after three successive runs, in which the RhB degradation performances showed a slight difference with the first oxidation cycle. This investigation is of great significance for the promising application of the heterogeneous Fenton catalyst with enhanced activity in the oxidative degradation of organic pollutants.

This paper presents a periodic density functional theory study on the adsorption of H, CO, and OH on Pt2Ru3 alloy surfaces containing different conformations of Pt and Ru atoms. The results show that for separate adsorption, H is preferentially adsorbed at Pt sites, whereas CO and OH are preferentially adsorbed at Ru sites. The adsorption strengths of H, CO, and OH are affected by ratio of the alloying atoms in top surface, the nature of the neighboring atom nearest to the adsorption site, and the conformation of alloying atoms in subsurface. We also investigated the coadsorption of CO with OH and the coadsorption of CO with H and found that the Pt–CO bond strength weakens. We also uncovered some information about the competitive adsorption behavior of adsorbates (CO, OH) with the aim of designing CO-tolerant Pt–Ru alloy catalysts.

The removal of organics by photoelectrocatalytic oxidation offers a viable option to remove the contaminants at low concentrations. In this paper, we propose a BiVO4 thin films synthesized via spray pyrolysis for photoelectrocatalyic oxidation of phenol with solar light. We compare the properties of BiVO4 with those of the commonly used photocatalyst TiO2. In addition, BiVO4 films with W gradient doping were fabricated and tested for improving the photocatalytic performance of BiVO4. X-ray diffraction, atomic force microscopy, incident photon to current efficiency and spectrophotometry have been conducted for BiVO4 films of different thicknesses, as well as for TiO2. The electrochemical impedance spectroscopy and dark conductivity measurements were conducted. Phenol removal has been measured for both the TiO2 and BiVO4 samples. The best performance was found to be for a 300 nm undoped BiVO4 film, being able to reduce the phenol concentration up to 30.0% of the initial concentration in four hours.

A novel and efficient photocatalyst of three dimensional (3D) Ba5Ta4O15 flower-like microsphere was synthesized via an alkaline etch under hydrothermal condition. The influence of reaction temperature, reaction time, and alkaline concentration on the morphology were investigated for the 3D Ba5Ta4O15 flower-like microsphere photocatalyst. The morphology and structure of the 3D Ba5Ta4O15 were characterized using x-ray diffraction, scanning electron microscope, transmission electron microscope, and high-resolution transmission electron microscopy. The results show that the elegant flower-like structure was composed of Ba5Ta4O15 nanosheets. The 3D Ba5Ta4O15 flower-like microspheres show a higher photocatalytic activity in the degradation of methylene blue under ultraviolet light than the bulk Ba5Ta4O15 microcrystal by the solid-state-reacted synthesized. The UV–vis diffuse reflectance spectra, photoluminescence spectra, volumetric adsorption method, and photocurrent response of the Ba5Ta4O15 photocatalyst were characterized indicated that the higher photocatalytic activity of flower-like Ba5Ta4O15 microspheres was due to the high crystallinity, large surface area and the effective charge separation.

We calculate, compare, and discuss the charge transport properties through quasi fullerene C40 obtained in three different electrode–C40–electrode testbeds by employing density functional theory combined with nonequilibrium Green's function, to predict the electronic structure of molecular junctions formed from copper, silver, and gold electrodes. We investigate various metrics such as chemical potential of electrodes, density of states, transmission spectra, Mulliken population, and molecular projected self-consistent Hamiltonian eigen states to develop a novel insight about the varying transport phenomenon as the metallic part of the scattering region is modified. We conclude that all the junctions exhibit strong metallic character displaying ballistic conductance of order of more than G 0 accompanied by pronounced ripples in their conductance spectrum and small rectifying behavior in their current spectrum. This rectifying behavior is found to stem from the asymmetric shifting of orbital energies with changing bias voltage due to change in relative charge transfer through central molecule C40.

Magnetic Fe3O4–polyhedral oligomeric silsesquioxanes (POSS) particles with Si-OH were prepared by hydrosilylation reaction between the Fe3O4–SiH and POSS with hydroxyl and vinyl groups. The magnetic Fe3O4–POSS particles were characterized by using transmission electron microscopy, scanning electron microscopy, Fourier transform infrared absorption spectroscopy, thermogravimetry, and vibrating sample magnetometry. The magnetic saturation value of Fe3O4–POSS particles was 18.77 emu/g. Polyacrylonitrile (PAN)/Fe3O4–POSS nanofibers mats were subsequently fabricated by electrospinning technique. The electret properties of PAN/Fe3O4–POSS nanofibers mats and their aerosol filtration property as electrets filter media were characterized. The stability of the surface potential was remarkably improved and the surface potential retention reached 50% for PAN/Fe3O4–POSS mats with 1 wt% Fe3O4–POSS. Compared with pure PAN, the charge retention of PAN/Fe3O4–POSS was increased by 21% and reached 52.40%. Moreover, the collection efficiency increased and the filter resistance decreased when the PAN nanofibers with Fe3O4–POSS were used as electrets filter media. Our study provided an effective method to prepare novel filter materials with high efficiency and low resistance.

There is growing interest in using instrumented indentation to characterize mechanical properties of soft materials, including tissue properties related to damage and disease. However, sample surface detection has been a major challenge. The multi-indent approach (MIA) is a novel method to indirectly detect the surface using data from multiple indents to determine the preload-induced indentation depth. Elastic modulus and shear modulus determined by MIA were equivalent to bulk measurements for 19 and 49 kPa gels. However, the traditional Oliver–Pharr approach significantly overestimated these properties. MIA is also important to accurate characterization of poroelastic properties and allows for much smaller probes and indentation depths to be used for all measurements. This is particularly important for poroelasticity, where the relaxation time scales with the size of the indenter. The novel approach helps to resolve the long-standing challenge of surface detection and has the potential to broaden the use of instrumented indentation for soft materials.

In this paper, the compressive behaviors of Zr-based bulk metallic glass (BMG) were experimentally studied under different testing conditions. To deeply reveal the inherent deformation mechanisms, numerical study was systematically conducted to analyze the shear banding evolution in BMGs, and the effect of testing machine stiffness, contact friction, and sample parallelism on the compressive ductility was therefore elucidated. Among them the effect of contact friction was carefully studied experimentally and the inherent deformation mechanisms was numerically analyzed in terms of the formation of shear bands. Free-volume theory was incorporated into ABAQUS finite element method code as a user material subroutine UMAT. The numerical method was firstly compared with the corresponding experimental results, and then parameter analyses were performed to discuss the impacts of testing conditions on the malleability of the BMG samples. The present work will shed some light on the interpretation of failure mechanisms in BMGs under different loading conditions.

A systematic study of SiC layer preparation in CH3SiCl3–Ar–H2 system by fluidized bed chemical vapor deposition was given. The phase, morphology, grain size, and crystal structure of the products were investigated based on series characterizations methods. Free silicon was formed at lower temperatures while free carbon was formed at higher temperatures. By introducing argon in the deposition system, silicon formation was suppressed and cauliflower structure with subordinate small particles was observed. The formation mechanisms of different microstructures were discussed. The experimental phase diagram of CVD SiC composed of three regions of SiC + Si, SiC and SiC + C was established and boundaries of the three regions were given. The phase diagram obtained can be used to guide the new applications of SiC series materials. The low-temperature dense SiC, porous SiC with tunable densities, small grained SiC, and composite SiC materials were prepared successfully, also it was indicated that SiC jointing technology can be developed based on the phase diagram accordingly in the future.

A dense monolithic intermetallic Al3Ti alloy was successfully synthesized via reactive sintering in vacuum using TC4 alloy and pure aluminum foils with appropriate initial thickness. Energy dispersive spectroscopy (EDS), x-ray diffractometry (XRD), and scanning electron microscopy (SEM) were used to characterize the phase and microstructure of Al3Ti alloy. Ultrasonic measurement was performed to evaluate the physical property of Al3Ti alloy. Different thermal analysis, thermogravimetry (TG) and differential scanning calorimetry (DSC) were used to assess the thermal property of Al3Ti alloy. The compressive tests were carried out on a universal load frame to determine the mechanical properties, including the compressive strength and failure strain of the fabricated intermetallic Al3Ti alloy. The current results indicated that the density of Al3Ti alloy is slightly higher than the theoretical density, the average Young's modulus is lower than the theoretical value. A trace of aluminum in Al3Ti alloy was detected, which is distinctly affected on the density, Young's modulus and mechanical properties of this titanium aluminide alloy. The stress–strain curves of Al3Ti alloy shows a linear elastic behavior without any plastic deformation, and the fracture features are the mixed fracture of transgranular and intergranular. Some other fundamental physical and mechanical properties of the Al3Ti alloy were also obtained in the present study.