Nitrogen-doped graphene (N-Graphene) has been extensively researched as the anode material for lithium-ion batteries, as the nitrogen doping provides massive active sites and improves the electrical conductivity and the ion diffusion kinetics, thus, significantly enhancing the lithium storage performance with reversible capacity and cycling stability. However, the high-rate performance and cyclability of the N-Graphene-based anodes are still to be achieved for fast-charging applications. Here, a new N-Graphene was successfully fabricated by annealing the commercial few-layer graphene with dicyandiamide. Along with the plenty of defects in the pristine graphene sheets, the doping of nitrogen effectively reduces the resistance and increases pore volume and the diffusion coefficient. Consequently, the N-Graphene anode exhibits outstanding lithium storage performance with superior high-rate performance and remarkable long-term capability (up to 10,000 cycles at 15 A g−1 with a reversible capacity of 133 mAh g−1). Further kinetic analysis reveals that this excellent electrochemical behavior during the rapid discharge/charge operations can be attributed to the enhanced diffusion-controlled and surface capacitive storages. Our process may lead to an alternative way for producing competitive N-Graphene anode materials for efficient lithium ion storage.

Iron disulfide (FeS2) has attracted extensive research interest due to its excellent catalytic efficiency. In this work, FeS2 was composited with carbon matrix to prepare a highly efficient electrocatalyst for hydrogen evolution. Two uniformly composites, namely, FeS2 @carbon nanotube (FeS2@CNT) and FeS2@carbon particle (FeS2@CP), were successfully prepared by pyrolysis and sulfuration processes. The structures of the synthesized composites were characterized by powder X-ray diffraction (PXRD), scanning electron microscope, transmission electron microscope, and X-ray photoelectron spectroscopy. It was found that the catalytic performances of the composites were obviously improved compared to pure FeS2. Moreover, compared to FeS2@CP, the FeS2@CNT nanotubes achieved a much lower overpotential and a smaller Tafel slope. The enhanced HER kinetics and hydrogen generation rate of FeS2@CNT may be due to its more efficient charge transport, uniform distribution of active sites, and higher surface areas. This work provides a new clue for the preparation of FeS2-based composite for hydrogen evolution.

Misfit strain, lattice parameter, polarization, permittivity, and tunability of Ba0.6Sr0.4TiO3 thin films onto BaxSr1−xTiO3-buffered stainless steel (SS) substrates are computed via a modified phenomenological model. When the Ba/Sr ratio of BaxSr1−xTiO3 buffer layer grows, the permittivity and tunability first increase and then decrease with the maximum at x = 0.75. The highest tunability of such films prepared by the sol-gel technique can reach 32.5% at the electric field of 320 kV/cm when x = 0.8. The strains are qualitatively analyzed through combining XRD, Raman, and theoretical calculation. The computed data are generally supported by experimental lattice parameters, permittivities, and tunabilities, which show that polycrystalline BST thin films with smaller compressive strain obtain higher dielectric response, and that inserting buffer layer could regulate the strains and dielectric properties of BST thin films.

The self-supported nanoflake-shaped Bi2Se2 was synthesized with the convenient method of microwave reaction, and adhered to the flexible carbon fiber felt. A series of electrochemical tests indicate that capacitance of Bi2Se2/CF electrode can reach 877.0 C g−1 (1 A g−1). Assembled by ligninbased carbon materials and Bi2Se2/CF electrode, the asymmetric capacitor has the energy density of 20.83 W h Kg−1 while the power density can reach 749.9 W kg−1. After circulating for 2000 times under 3 A g−1, the remaining capacitance retention reaches 81% of the initial one.

Herein, precursor assembly of polyanion with pH sensitive molecule, Bis[2-(4-HydroxyPhenyl)BenzImidazole] (BHPBI), was reported to amplify layer-by-layer (LBL) exponential growth. The promoted polyelectrolyte diffusivity was responsible for the amplified LBL deposition efficiency. The release behavior of BHPBI and the anti-oxidant stress function of the film were both evaluated. The constructed multilayer film was tested to be potential drug loading and delivery system for BHPBI.

Electrolytic manganese dioxide (EMD) is the critical component of the cathode material in modern alkaline, lithium, and sodium batteries. Aimed at the remediation of EMD crystalline structures, this research explored the effect of external power-supplying models on EMD structure regulation. The chaos electro circuit was found to impact the characteristics of EMD such as the crystalline structure, also the nanostructure morphology, and the hysteresis behavior.

In this paper, the nonmetallic Si4+-doped modified lanthanum aluminate (LaAlO3) solid electrolyte for the first time, which has particular scientific significance, and LaAl1−xSixO3−δ material was successfully prepared by the sol–gel method. LaAl1−xSixO3−δ is a ceramic material sintered at 1100∘C for 2 h in an air atmosphere. The surface microstructure and electrochemical properties of the samples were tested by multiple characterization methods. The results show that the LaAl1−xSixO3−δ has good sintering activity, high crystallinity, and a grain radius of approximately 25 nm. At 800∘C, the ionic conductivity is above 1.05E− 04 S⋅cm−1 and the activation energy is lower than 1.19 eV.

Lithium-rich oxide cathode material focuses the attention of many researchers due to its excellent electrochemical performance for lithium–ion batteries. Further improvement on the performance with a strong operability approach can be beneficial to its industrialization and commercialization. In this work, the effect of powder compaction pressure in sintering process on the electrochemical performance of Li1.2Mn0.54Ni0.13Co0.13O2 cathode material is investigated. Four cathode materials under different powder compaction pressure are synthesized by sol–gel method. The XRD analysis results reveal their consistency on the crystal structure. But there is a slight difference on particle size and microstructure found by SEM analysis. Electrochemical tests show that a cathode material under medium compaction pressure exhibits the best performance with a discharge capacity of 170.3 mAh⋅g−1 at the rate of 200 mA⋅g−1 with 89.35% retention after 100 cycles. This work reveals that the powder compaction pressure does have influence on the cycle and rate performance and this relation is not proportional and linear.

Nickel nanoparticles (Ni NPs) are attracting more and more attention in the field of electrochemistry due to their high conductivity and good catalytic properties. However, Ni NPs are susceptible to corrosion or agglomeration, leading to low stability. In this work, [email protected] nanomaterials ([email protected]) were prepared by pyrolysis nickel-based metal-organic framework (Ni-MOF) template, and characterized by powder X-ray diffraction (PXRD), transmission electron microscopy, scanning electron microscopy, Brunauer–Emmett–Teller method, and X-ray photoelectron spectroscopy (XPS). The prepared [email protected] composite reveals uniform core-shell structure, where the thin carbon shell not only protects the Ni NPs from being corroded, but also accelerates the migration of electrons, so as to promote its sensing performance. [email protected] composite presented as a black powder with mesoporous structure. The average size of Ni NPs was about 15.01 nm with a standard deviation of 3.21 nm. The specific surface area of [email protected] was as high as 116.12 m2g−1, which is beneficial to increase the effective surface area of the modified electrode. These structural advantages enhance its electrochemical performance toward paracetamol (PA) sensing. The [email protected] modified electrode has high sensitivity for quantitative detection of PA. The linear ranges were determined to be 0.570 μM and 70432 μM with a low detection limit of 0.028 μM (S/N = 3). In addition, due to its excellent electrochemical performances, the constructed electrode was used to detect PA in real water samples. This work expands the application of Ni- and C-based composites in electrochemistry sensing.

In this study, the post-annealing process of garnet-type electrolyte films produced by the powder aerosol deposition method was optimized by utilizing high-power LEDs. The post-annealing time was greatly reduced from hours to several seconds. The film conductivity at room temperature could be increased by three orders of magnitude from 5.0 ⋅ 10−8 S cm−1 to 5 ⋅ 10−5 S cm−1. For the first time, the required energy for this almost complete conductivity restoration could be quantitatively estimated.

NASICON-type Li1.5Al0.5Ge0.5P3O12(LAGP) is one of the most promising inorganic solid-state electrolytes (SSEs). However, its practical applications have been hindered due to the high grain boundary resistance and poor sintering performance. In this work, we introduce a novel LiBF4 sintering aid into LAGP to promote the growth of grains, decrease grain boundary resistance, and supplement the loss of lithium. The experimental results show that the ionic conductivity of LAGP-0.5 wt% LiBF4 has the highest ionic conductivity (3.21 × 10−4S/cm), grain boundary impedance decreases from 162.2 Ω to 35.2 Ω, the relative density increases from 93.6% to 96.5%, and no impurity phase is observed in LAGP–0.5 wt% LiBF4. At the same ionic conductivity, the sintering temperature of LAGP without LiBF4 and with a small amount of LiBF4 decreases from 800∘C to 700∘C. The Li/LAGP-LiBF4/LiFePO4 cell presents excellent cyclic stability (capacity retention of the discharge capacity is still 117.5 mAhg−1 after 100 cycles) and a high initial discharge capacity of 164.2 mAhg−1 at 0.2 C.

Li4Ti5O12(LTO) is one of the most popular Li+-storage anode materials. However, the influences of different operating temperatures on the electrochemical performance of LTO and the underlying mechanisms are still unclear. Herein, we systematically investigate its temperature-dependent electrochemical performance, electrochemical kinetics, and crystal-structural evolution at −10∘C, 5∘C, 25∘C, 45∘C, and 60∘C. When the operation temperature increases from −10∘C to 45∘C, more intensive electrolyte decomposition increases the irreversible capacity in the first cycle, which decreases the initial Coulombic efficiency. Meanwhile, the electrochemical kinetics becomes faster, leading to reduced electrode polarization, faster Li+Transport, and higher rate capability. Finally, the maximum unit-cell-volume shrinkage enlarges, resulting in the decay of the cyclic stability. However, when the temperature further rises to 60°C, the rate capacity and cyclic stability rapidly decay due to the severe electrolyte decomposition catalyzed by Ti4+ and the formation of thick solid electrolyte interface (SEI) films.

Co2FeGa Heusler alloy nanowires with diameters of about 30, 60 and 110 nm were prepared using a template-assisted electrochemical deposition method. We observe the different angular dependences of coercivity and remanence ratio for these samples. Magneto-transport measurements show that the 30 nm diameter Co2FeGa nanowires has a large magnetoresistance up to −56%, which is much higher than 60 and 110 nm diameter Co2FeGa nanowires. This is the first time that the magnetoresistance properties of Co2FeGa nanowires were presented.

The inactivation ability of SARS-CoV-2 (COVID-19) was examined using two types of transparent Cu2O thin films with different crystallinities on a Na-free glass substrate. The low-crystallinity Cu2O thin film, which was fabricated by irradiating 254 nm ultraviolet (UV)-light with an intensity of 6.72 mW cm−2 onto a spin-coated precursor film involving Cu2+ complexes at room temperature, exhibited an outstanding COVID-19 inactivation ability to reduce 99.999% of the virus after 1 h of incubation. The X-ray diffraction results of the UV-irradiated thin film indicated a cubic Cu2O lattice with a small crystallite size of 2 ± 1 nm. Conversely, the high-crystallinity Cu2O thin film with a crystallite size of 16 ± 3 nm, obtained by heating a spin-coated precursor film containing another Cu2+ complex, showed a negligibly low inactivation activity at the same level as the Na-free glass substrate. The eluted concentrations of Cu ions from both Cu2O thin films were analyzed after immersion in Dulbecco’s modified Eagle’s medium (DMEM) for 0.25–2 h. The eluted Cu–ion concentration of 1.16 ppm was observed for the UV-irradiated thin film by DMEM immersion after 1 h, but that of 0.04 ppm was observed for the heat-treated thin film. This indicated that an important factor of virus inactivation on Cu2O thin films is highly related to the elution of Cu ions that occurred from the surface in the medium.

Developing photosensitizers with high durability is desirable to boost the practical application of photocatalytic hydrogen evolution. Herein, referring to the successful strategy in the field of light-emitting electrochemical cells, the reported Ir(III) complex with intramolecular π–π interaction, Ir2, is used as a photosensitizer to explore its durability. Photocatalytic hydrogen evolution experiment exhibits that the durability of Ir2 is significantly improved with the duration of 39 h, which is three times longer than that of the classical Ir(III) complex Ir1 (ca. 13 h) under the same condition. As revealed by theoretical calculation, the incorporation of intramolecular π–π interaction inhibits the rupture of metal–ligand bond in the excited state, thereby reducing the possibility of complex degradation. This is a novel approach to achieve a durable Ir(III) photosensitizer, which stimulates new molecular engineering endeavors. The finding proves the applicability of molecular design strategy in the field of light-emitting electrochemical cells to the photocatalytic hydrogen evolution system, thus boosting the cross integration of different disciplines.

Two-dimensional (2D) titanium carbide (MXene) is considered as a potential anode material for lithium-ion batteries (LIBs) by virtue of its unique structural and electronic properties. However, its performance for actual energy storage is seriously affected by the loss of transition metal elements during the preparation process of MXene. Herein, using a simple hydrothermal method, vanadium was successfully doped into the delaminated Ti3C2Tx (named as V-doped Ti3C2Tx). As-prepared V-doped Ti3C2Tx MXenes provide more active sites and lower Li+ diffusion resistance. As a result, their rate performance is significantly improved compared to that of pristine Ti3C2Tx. Additionally, its discharge capacity retains a value of 63.6 mAh g−1 after 10,000 cycles at 10 A g−1.

Transparent and conductive quaternary gallium-titanium-zinc-oxide films were grown on glass substrates by radio-frequency magnetron sputtering. The effects of growth temperature on structure, morphology, electrical, and nonlinear optical properties of the films were investigated systematically. All the deposited films possess hexagonal wurtzite structure with (002) preferred crystallographic orientation. The obtained optical bandgaps of the deposited films are larger than that of pure zinc oxide, which is ascribed to the reduction in band tail width. The film deposited at growth temperature of 375∘C exhibits the optimum crystalline quality with the lowest dislocation density of 1.4 × 10−4nm−2, the highest visible light transparency of 82.06%, the minimum sheet resistance of 11.2 Ω/sq, and the maximum figure-of-merit of 1.24 × 10−2Ω−1. The present findings indicate that the gallium-titanium-zinc-oxide films are promisingly utilized as transparent conductive layer. The refractive index and extinction coefficient of the deposited films were estimated by using spectrum fitting approach. A normal optical dispersion behavior was observed in visible region, while an anomalous dispersion behavior appeared in ultraviolet region. In addition, the nonlinear optical parameters were obtained. This first-hand information is useful for future rational design of multicomponent zinc oxide semiconductor materials for optoelectronic applications.

In this study, WS2–WO3 particles were successfully synthesized by a solvothermal liquid-phase oxidation process under various conditions and their gas sensing performance was evaluated at room temperature. The sample synthesized in ethanol-rich solvent at 210∘C showed excellent gas sensing performance. It is suggested that the crystalline phase and the particle morphology, which are essential for improving gas sensing performance, are effectively controllable by the present liquid phase oxidation process.

Multicolor nitrogen-doped graphene quantum dots (NGQDs) were prepared via one-pot method and purified by column chromatography to obtain three NGQDs with different emission colors, i.e. blue emission (B-NGQDs), cyan emission (C-NGQDs), and yellow emission (Y-NGQDs). The multicolor NGQDs were combined with InGaN chip to fabricate light-emitting diode (LED) that emitted blue, cyan, and yellow light, respectively. Moreover, reducing the amount of Y-NGQDs used could construct a white LED (WLED) with color coordinate of (0.324, 0.334).

The electronic, the thermal, and the optical properties of hexagonal MgX monolayers (where X = C, N, and O) are investigated via first principles studies. Ab-initio molecular dynamic, AIMD, simulations using NVT ensembles are performed to check the thermodynamic stability of the monolayers. We find that an MgO monolayer has semiconductor properties with a good thermodynamic stability, while the MgC and the MgN monolayers have metallic characters. The calculated phonon band structures of all the three considered monolayers show no imaginary nonphysical frequencies, thus indicating that they all have excellent dynamic stability. The MgO monolayer has a larger heat capacity then the MgC and the MgN monolayers. The metallic monolayers demonstrate optical response in the IR as a consequence of the metal properties, whereas the semiconducting MgO monolayer demonstrates an active optical response in the near-UV region. The optical response in the near-UV is beneficial for nanoelectronics and photoelectric applications. A semiconducting monolayer is a great choice for thermal management applications since its thermal properties are more attractive than those of the metallic monolayer in terms of heat capacity, which is related to the change in the internal energy of the system.