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Mechanical robustness, biocompatibility, and antibacterial performances are key features for materials suitable to be used in tissue engineering applications. In this work, we investigated the link existing between structural and functional properties of TiCu(Ag) thin films deposited by physical vapor deposition magnetron sputtering on Si substrates. The thin films were characterized by X-ray diffraction (XRD), nanoindentation, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The TiCu(Ag) thin films showed complete amorphous structure and improved mechanical properties in comparison with pure Ti films. However, for contents in excess of 20% Ag, we observed the appearance of nanometric Ag crystallite. The TiCu(Ag) thin films displayed excellent biocompatibility properties, allowing adhesion and proliferation of the human fibroblasts MRC-5 cell line. Moreover, all the investigated TiCu(Ag) alloy display bactericidal properties, preventing the growth of both Pseudomonas aeruginosa and Staphylococcus aureus. Results obtained from biological tests have been correlated to the surface structure and microstructure of films. The excellent biocompatibility and bactericidal properties of these multifunctional thin films opens to their use in tissue engineering applications.

Molecules that are difficult to convert catalytically often require a complex and specially tailored catalyst composition. Catalytic alkane dehydrogenation is an interesting example, where theoretical ab-initio and kinetic meso-scale simulations can provide the understanding of the performance improvement when the catalyst composition is altered. Herein, we study non-oxidative dehydrogenation of propane and butane over variously doped (Na, Li, K, Mg, Ca, or Cs) chromium oxide using first principles. The reaction pathway for the conversion of propane to propene/propyne and of butane to 1- and 2-butene is studied using density functional theory with the Hubbard U correction. Energies and kinetic parameters describing the adsorption, desorption, and surface reactions are used in mean-field microkinetic and kinetic Monte Carlo simulations. The process was modelled at industrially relevant temperatures, pressures, and feed gas flow velocities. Calculating the catalytic conversion, selectivity to products, and activity trends show that surface doping enhances the conversion and activity. The highest conversion for most dopants is achieved at temperatures below 850 K and atmospheric pressure, where the activity is significantly improved compared to the non-doped Cr2O3 catalyst.

Ag2S quantum dots decorated TiO2 nanosheets with highly reactive {001} facets exposed were grown on carbon fibers by hydrothermal technology and successive ionic layer adsorption and reaction method. The ternary CFs-TiO2-Ag2S heterostructure exhibits excellent photoelectrochemical protection performance for the coupled 304 stainless steel. Ag2S quantum dots with narrow band gap enhance the sunlight harvest of the hybrid. The carbon fibers act as transmission channels for the photo-induced electrons that facilitate the photogenerated carrier separation. Schottky barrier formed in the heterostructure interface and the increased inner electric field promote the electron dissociation and migration from the hybrid semiconductor to the coupled metal, resulting in enhancement of photoelectrochemical protection of the 304 stainless steel.

The fabrication of nanocarbons possessing ultrathin graphitic structure and ultrahigh nitrogen doping simultaneously remains challenging so far. Herein, we develop a novel and versatile strategy to prepare ultrahigh nitrogen-doped hierarchical porous carbon with ultrathin graphitic framework (NHPCs), through the Schiff-base reaction of melamine and terephthalaldehyde in the presence of lithium oxide, as high-performance anodes for rechargeable lithium ion batteries. During one-pot solid-phase interface reaction, Li2O was used to absorb the in-situ generating H2O enhancing the formation of Schiff-based networks and LiOH was in-situ obtained, which can be used as active agent to increase the BET surface areas of final carbons. The obtained NHPCs present 3D hierarchical honeycomb-like morphology, ultrahigh nitrogen content up to 12.2 wt%, large specific surface area of 1260 m2 g−1. These unique structural properties allowed for fast ion diffusion and rapid electron transport, and offered enriched active sites for lithium storage. NHPCs presented a high reversible capacity of 880 mAh g−1 at 100 mA g−1 even after 100 cycles, and exceptional rate capability with 301 mAh g−1 at 3000 mA g−1, outperforming most reported nano‑carbons. Therefore, this strategy will open a new way to prepare heteroatom-doped porous carbons with a controllable hierarchical structure, for high-performance energy storage.

The upgrading of lignin-derived bio-oils involves a HydroDeOxygenation (HDO) reaction through either the Hydrogenation (Hyd) or the Direct DeOxygenation (DDO) route, the latter limiting hydrogen consumption. Herein, dispersion-corrected DFT has been used to evaluate the adsorption behavior of phenol (as a representative model of bio-oils) and two by-products (water and CO) over various crystalline and amorphous silica surfaces to evaluate their potential selectivity (DDO/Hyd) and efficiency (low inhibiting effect) for HDO processing. Phenol can adsorb through three modes, flat π-interaction, flat O-interaction or perpendicular O-interaction. All crystalline surfaces show a preference for the flat π-interaction, which is expected to promote the Hyd route. Over amorphous surfaces the flat O-interaction dominates, and a very specific and strong interaction (around −120 kJ/mol) was found on SiO2-3.3 and SiO2-2.0 surfaces where the phenol molecule loses its aromaticity, which is very promising for its degradation under catalytic conditions. In addition, this makes those surfaces very efficient to adsorb selectively phenol in presence of water and CO. Remarkably, on all silica surfaces, the interaction energy of CO is nearly negligible, which makes them more attractive for HDO process compared to sulfide catalysts with respect to the inhibiting effect criteria.

Dual-functional porous copper films were prepared by dynamic hydrogen bubble template (DHBT) technique to achieve in situ SERS monitoring of electrocatalytic reaction. The morphology and SERS activity of porous copper films were effectively modulated by electrolyte additive, current density, and deposition time. The interfacial evolution behaviors of porous copper films were monitored by in situ synchrotron radiation X-ray imaging. The three-dimensional porous copper films in the presence of CTAB additive present a thinner leaf-like dendritic structure and excellent SERS activity. Although the diverse morphologies of porous copper films are obtained with inorganic additives including (NH4)2SO4, Na2SO4, or NaCl, they are deleterious to the SERS activity due to the microstructural changes of copper films, even significantly lower than that of the additive-free condition. The obtained porous copper films exhibit high sensitivity (10−9 mol/L) and good reproducibility for efficient SERS detection. Furthermore, the electrocatalytic reduction process of 4-nitrophenol on the porous copper films was successfully in situ monitored based on their excellent SERS activity.

The combination of ferrite and carbon materials with core-shell nanostructures has attracted tremendous interest in microwave absorption field. Herein, Fe/Fe3C-C core-shell nanoparticles with diameters of 10–70 nm were synthesized by one-step metal-organic chemical vapor deposition. The nanocores of the nanoparticles can be tailored from Fe3C, to Fe3C/Fe, and then Fe by simply changing the reaction temperature. The Fe/Fe3C-C core-shell nanoparticles exhibited an optimal reflection loss (RL) value of −58.5 dB and effective absorption bandwidth (frequency range for RL

We studied the applicability of Pulsed Laser Deposition (PLD) as a particle engineering method in the field of drug preformulation. Improving the dissolution and thereby the bioavailability of poorly water-soluble compounds is still a challenging task in pharmaceutical formulation. It was shown earlier that particle size reduction or the development of stable amorphous forms may both facilitate drug absorption. Using ibuprofen as a model drug, we studied the ablated particles obtained by pulsed-laser-beam irradiation of ibuprofen tablets. Nanosecond and femtosecond laser pulses (KrF excimer laser, λ = 248 nm, FWHM = 18 ns; 600 fs) were applied at various ambient pressures (10−4 mbar to 1 bar). The ablated particles were deposited for further analysis by FTIR, Raman Spectroscopy, XRPD, DSC and SEM. We found that all deposits prepared in vacuum by ns-pulses were chemically identical with ibuprofen, but their morphology varied depending on the applied pressure. At higher pressures (10 mbar to 10−1 mbar) the deposits exhibited similar crystalline morphology as the initial ibuprofen, while at lower pressures (10−2 mbar to 10−3 mbar), the deposits were rather amorphous. Using fs-pulses, molecular decomposition occurred at all background pressures. We have established that PLD with ns-pulses is a promising technique in the field of drug preformulation.

It is important to be able to control the physical and chemical integrity of carbon-based porous monolith structures while being tailored for targeted analytical, energy and catalytic based applications. A set up using a CO2 laser in continuous mode (CW CO2 laser) was implemented to cut fragile and porous carbon monolithic (CM) and nanotemplated carbon monolithic (NTCM) rods into discs with a prescribed thickness and dimensional integrity (denoted as LCM and LNTCM, or LCMs). Changes in structure, porosity and composition of LCMs were induced by the efficient thermal energy afforded by the CW CO2 laser irradiation under tightly controlled process conditions. The main effects observed before and after laser cutting were studied in comparison with traditional scalpel blade cutting of carbon monolithic (SCM). FE-SEM images confirmed that the resulting LCMs exhibited a more open, interconnected macroporous structure and smoothed mesopores to a depth of approximately 5 μm, while the structure of the bulk section remained intact. Minimal changes in chemical compositions were confirmed by XPS. Raman spectroscopy revealed a modest increase in the graphitic content on the cross sections of LCM discs. Phenol and Bisphenol A (BPA) was used as a model analyte for demonstration of resulting discs adsorption performance.

The durable superhydrophobic and oleophobic coating has been fabricated based on perfluorodecanethiol fluorosilicone polyurethane (PFDT-FSPU) and thiol-modified cellulose substrate. The PFDT-FSPU was prepared from a fluorosilicone polyurethane and perfluorodecyl mercaptan via thiol-ene click chemistry. The thiol-modified cellulose substrate was obtained by a condensation reaction of 3-mercaptopropyl triethoxysilane (MPTES) and hydroxyl of cellulose substrate. The crosslinked network structure was formed by radical polymerization of double bonds in the PFDT-FSPU when the polyurethane was irradiated with ultraviolet light, and it was anchored on the surface of the cotton fibers by click reaction between the thiol-modified cellulose substrate and the PFDT-FSPU. FTIR spectroscopy illustrates that the synthesis of PFDT-FSPU and Raman spectroscopy characterizes the structure of thiol modified cotton fabric. The water and hexadecane contact angle were 158.2° and 128.3° respectively, and oil-repellent grade reached to 8 and antifouling grade was 4, which indicated that the coated fabric exhibited good amphiphobic and antifouling properties. Most importantly, the coated fabric showed excellent durability and can still maintain the superhydrophobicity and oleophobicity even after 600 cycles of abrasion or 30 times of washing cycles or 168 h of accelerated aging test.

The tactic of embedding functional nanomaterials into ultrafiltration (UF) membranes has been investigated in order to augment the integrated properties of the hybrid membranes. Mixing of hydrophilic inorganic nanoparticles or nanofillers into the polymeric membranes to form organic-inorganic nanocomposite membranes were found to be quite effective in improving membrane hydrophilicity. In the present study, polysulfone (PSf) membrane of three different compositions (9, 12, 18 wt%) in-situ immobilized with silver nanoparticles were fabricated using phase-inversion technique. The surface morphology of the membranes were studied by field emission scanning electron microscope (FESEM). The uniformity of the distributed nanoparticles and the elemental compositions were proved by energy dispersive x-ray Spectroscope (EDS). BET (Brunauer-Emmett-Teller), nitrogen adsorption measurement has revealed the increase in surface area from 10.15 to 18.85 m 2 /g for polysulfone membrane and 12.31 to 20.62 m 2 /g for silver-polysulfone (Ag-PSf) membrane. The surface charges of the fabricated membranes were studied using zeta potential measurements. Furthermore, water flux and sulfate rejection measurements were also carried out using a cross-flow membrane unit. Among the three different compositions, 12 wt% PSf-Ag membranes had significantly higher rejection rate than that of the other membranes.

Semiconductor heterojunctions with fast photogenerated carrier transfer have great potential for environmental remediation. However, most of the semiconductor heterojunctions reported so far are surface lipophobic and have low affinity for most lipophilic organic pollutants. Herein, we developed a facile hydrothermal method coupled with a self-assembly strategy to synthesize a novel MoCdS3 photocatalyst modified by hexadecyl trimethyl ammonium bromide (HDTMA) surfactant (HDTMA-MoCdS3). Detailed characterizations, including SEM-EDS, HRTEM, XRD, FTIR, XPS, Raman spectroscopy and optical contact angle, were carried out to confirm the structure and surface properties of the crystalline heterojunction. Further photoelectrochemical tests proved the superior performance of HDTMA-MoCdS3 for separation of photogenerated carriers compared to bulk CdS and MoS2. Bisphenol A and methyl orange were chosen as the model pollutants to investigate the capture performance and further photocatalytic ability of HDTMA-MoCdS3. By synergistic effect of rapid adsorption of pollutants and high capacity for photogenerated carrier transfer, the HDTMA-MoCdS3 composites exhibit outstanding activity and stability for photodegradation of organic contaminants.

Graphene film formation by carbon deposition from gaseous phase on nickel substrates is investigated using scanning tunnel microscope (STM) unit embedded into reactor of the chemical vapor deposition (CVD) system. The microscope was designed to provide STM measurements at the same 1 μm × 1 μm region on the sample surface before and just after CVD synthesis without taking the sample out of the reactor. The peculiarities of graphene deposits formation on polycrystalline nickel substrates are revealed using developed CVD-STM system. The topology features are analyzed in combination with Raman spectroscopy data. One of particular features revealed in this study is nanobubbles formation and collapse on graphene film surface. We are discussing possible mechanisms of this phenomenon.

Polyaniline (PANI), Graphene Oxide (GO) and PANI-GO nanocomposite were prepared using in-situ polymerization and Hummer's method. GO can improve the thermoelectric properties (TE) of polyaniline by varying the concentration of GO. The morphological and structural studies confirm the uniform growth of PANI on the surface of GO during polymerization and leading to an order crystalline structure in amorphous matrix. Raman analysis and Fourier transform infrared spectroscopy (FTIR) studies shows strong pi-pi interaction of PANI over the surface of GO. And other interactions such as hydrogen bonding and electrostatic interaction between PANI and GO gives good support to increase their TE properties. The TE properties of PANI and PANI-GO nanocomposite have been investigated in the temperature range of 298 to 363 K. The electrical conductivity, Seebeck co-efficient and power factor of the sample PG2 (20% GO) is around 1489 S/cm, 59 μV/K and 52.11 10−7 W/K2 cm at room temperature (RT), which is 1.2 times, 1.15 times and 1.5 times higher than pure polyaniline. And the sample PG2 (20% GO) showed the highest ZT at 363 K of 0.8 and at room temperature 0.4, which is 1.25 times and 1.23 times higher than sample PP.

In this study, photocatalytic properties of a graphene carbon nitride (g-C3N4) oxygen-deficient BiOCl (ODBOC) nanocomposite, which was assisted by the distinguished properties of graphene quantum dots (GQDs/gCN/ODBOC), in the decomposition of harmful organic vapors were investigated. The GQDs/gCN/ODBOC ternary composite was prepared using a facile chemical-mixing method. The presence of oxygen vacancies in ODBOC and the GQDs/gCN/ODBOC nanocomposite was confirmed by electron spin resonance and X-ray photoelectron spectroscopy. Compared to pristine BiOCl, ODBOC exhibited a higher performance, while compared with those of the selected photocatalyst counterparts, GQDs/gCN/ODBOC exhibited a higher performance; particularly, the removal efficiency of hexanal over this catalyst increased up to 95%. The superior performance of the above photocatalyst was related to two distinguished properties of GQDs: improved visible-light absorption by their upconverted photoluminescence and promoted charge-separation ability by their electron attraction properties, as well as the Z-scheme charge transfer at the junctions between g-C3N4 and ODBOC. In addition, the GQDs/gCN/ODBOC fabricated using a GQD solution of 5 mL revealed the highest performance and satisfactory photochemical stability during recycling tests. Finally, the photocatalytic mechanism for the pollutant degradation over GQDs/gCN/ODBOC was proposed on the basis of band-energy structures and hydroxyl radical measurements.

This paper presents experimental results on the effect of various operating parameters on the synthesis of gas hydrates by a method based on the self-organizing process of boiling-condensation of a hydrate-forming gas in the volume of water. A series of experimental studies were carried out under various conditions, and optimal conditions that affect the process of hydrate formation were determined. The influence of the water column height and the boiling intensity of the hydrate-forming gas on the hydrate formation process is estimated. Freon 134a was used as a hydrate-forming gas in the studies.

It is of significant academic value to find a new type of eco-friendly photocatalyst with high-efficiency, low-cost, which can be applied to the photocatalytic synthesis of N2/H2O to ammonia. In this paper, pitch-based graphene oxide (GO) is obtained by using petroleum pitch as a carbon source (Hummers Method). Then, the ZnS nanoparticles were loaded onto the pitch-based GO sheet to get the composite photocatalyst ZnS/GO of different GO contents (Hydrothermal Method). The performance of ZnS/GO photocatalytic synthesis of N2/H2O to ammonia was studied while characterizing the material structure and photoelectric properties. The results showed a similar structure and performance with general graphite-based GO. The presence of GO structure not only enables the composite catalyst to enhance electron transfer by inhibiting the recombination of the photogenerated electrons and holes pairs, but also improves activation and adsorption N2 properties and photocatalytic ammonia synthesis with N2/H2O performance. The NH4+ yield was 910.6 μmol/L·g cat after 6 h photocatalytic reaction, which was about five times of NH4+ yields on pure ZnS as a photocatalyst under the same conditions.

A triazole (1-(p-tolylthio)-1H-1,2,3-triazole-4-carboxylic acid, TTC) film was prepared via an in-situ click-assembling reaction between tosyl azide (TA) and propiolic acid (PA) on Cu, Cu2O and CuO substrates. Its surface wettability, antibacterial activity and anticorrosion ability were evaluated by surface characterizations, antibacterial testing and electrochemical measurements. The modified-Cu2O film exhibits the best overall performance. The anticorrosion protection efficiency of the modified-Cu2O film for copper is 91.1%. The modified-Cu2O film shows a superior hydrophobicity with a contact angle of 137° and it also has the best antibacterial activity. The FT-IR and surface analysis (SEM and XPS) reveal that the excellent anticorrosion ability of the modified-Cu2O film is mainly due to the massive TTC film assembled on its surface. The large amount of TTC also contributes to the best hydrophobicity and antibacterial activity. The theoretical calculations show that the TTC film is formed via the horizontal adsorption of a triazole ring and O atoms in the TTC molecule.

Na0.44MnO2 is expected to be a cathode material with an excellent electrochemical performance for sodium ion batteries due to its unique 3-dimensional (3D) S-type tunnel structure. However, the high cut-off working potential of Na0.44MnO2 is usually restricted below 4.0 V (vs. Na/Na+) to inhibit fast capacity fading. Although pristine Na0.44MnO2 submicron rods deliver a high initial discharge capacity of 108.0 mAh g−1 at 0.4C (1C = 121 mAh g−1) in the wide voltage range of 2.0–4.5 V however the discharge capacity reduces to 80.5 mAh g−1 after 200 cycles. For improving the electrochemical properties under high voltage, Al2O3 coated Na0.44MnO2 is prepared by a wet-coating process and the coating amount is optimized. The as-prepared 2 wt% Al2O3-coated Na0.44MnO2 submicron rods possess the best electrochemical performance between 2.0 V–4.5 V, which deliver an initial discharge capacity of 109.8 mAh g−1 at 0.4C and maintain capacity retention of 93.2% after 200 cycles. Moreover, in long-term cycle performance at high current density (4C) between 2.0 and 4.5 V, 2 wt% Al2O3-coated Na0.44MnO2 can retain 79% capacity after 500 cycles. The mechanism of elevated electrochemical performance for Al2O3-coated Na0.44MnO2 submicron rods in high voltage is systematically investigated.

In this work, NiCo2O4@TiO2 electrodes based on micro-region heterojunctions were synthesized by a simple one-step hydrothermal method. The material characteristics of resultant samples were characterized by XPS, XRD, SEM, HRTEM and BET. Compared with NiCo2O4 electrodes prepared with the same hydrothermal method, the NiCo2O4@TiO2 electrode shows higher electrochemical performance, cycling stability and lower charge transfer resistance. Specifically, the mass specific capacitances of NiCo2O4 and NiCo2O4@TiO2 electrodes are 564.3 F · g−1 and 1085.7 F · g−1 at current density of 5 A · g−1 and retained 84.4% and 95.5% after 10,000 cycles, while the Rct of NiCo2O4 and NiCo2O4@TiO2 are 1.72 Ω and 0.18 Ω, respectively. For practical applications of NiCo2O4@TiO2 electrode, a NiCo2O4@TiO2//AC two-electrode system was assembled and the performances were tested to achieve 255.9 F · g−1 at current density of 2.5 A · g−1. Additionally, the corresponding energy density and power density were recorded as 91 wh/kg and 4 kw/kg. The superior electrochemical performance and cycle stability of NiCo2O4@TiO2 electrode might be attributed to the higher specific surface and micro-region heterojunctions for enormous future applications.

The kernel of photocatalytic technology is to exploit photocatalytic materials with high efficiency, stability and easy recovery. Herein, we designedly prepare a magnetic quantum dot (Fe3O4 QDs) as co-catalyst to modify Z-scheme Bi2O4/g-C3N4 (Bi/CN) composite photocatalyst via combining calcination with hydrothermal method. The morphology, chemical composition and physicochemical properties of photocatalysts are systematically analyzed by a series of characterization means. The experimental results explicitly render that the optimum Fe3O4-QDs/Bi2O4/g-C3N4 (FeQDs/Bi/CN) has outstanding photocatalytic performance than that of Bi2O4, g-C3N4 and Bi2O4/g-C3N4 (Bi/CN), which is chiefly imputed to the synergistic effect of Z-scheme heterojunction system and Fenton reaction. The Z-scheme heterojunction is conductive to accelerate charge carrier separation and makes electrons and holes retain higher redox ability. Fe3O4 QDs can promote visible light absorption and generate more hydroxyl active ( OH) substances through Fenton reaction. Furthermore, the magnetic photocatalyst is liable to separate under the action of external magnetic field, which ensures that is convenient for industrial application. The mechanism of photocatalytic degradation is discussed in detail by capturing experiments, ESR and liquid fluorescence detection. This work unveils more possibilities for modifying Z-scheme heterojunction system to improve photocatalytic performance.

Large quantities of free standing quasi mono-disperse silicon nanocrystal/silicon oxide core-shell structured particles have been segregated by a cyclic process of sonication and centrifugation of mechanically milled and chemically treated colloidal suspension of silicon powders in ethanol medium. Narrowing of size distribution with the enhancement of centrifugation time has been evidenced from different structural characterisations as well as optical absorption and photoluminescence study. Gradual shifting of photoluminescence peak positions towards higher energy region in samples, prepared through longer centrifugation time, is also detectable with unaided eye when different samples are exposed to laser beam of wavelength ~405 nm. Controlled optoelectronic properties of the final sample achieved after four such cycles indicate a narrow core size distribution centering at 2.15 nm; can also be evidenced from the TEM micrograph.

First-principles calculations were performed to investigate the catalytic activity of Li O2 batteries based on TiC and X-doped TiC (X = B, N, Al, Si, and P) materials as potential cathode catalysts. Interfacial models of LixO2 (x = 4, 2, and 1) intermediates adsorbed on doped TiC surface were used to simulate the structural evolution during discharging/charging process. The catalytic activity was quantitatively assessed by specific ORR/OER overpotential, and some intrinsic factors affecting the catalytic activity of doped TiC were determined based on the structure-activity relationships established. The catalytic activity of doped TiC can be divided into two groups, wherein B-, N-, and P-doped TiC have better catalysis than Al- and Si-doped TiC. Among them, B-doped TiC displays the lowest ORR overpotential, suggesting that B-doped TiC has the best catalytic activity of ORR. The stronger (Li2O)2/Li2O2/LiO2 adsorption energy induces lower ORR and OER overpotentials. The stronger Li+ desorption energy attracts lower ORR overpotential, while the weaker O2 desorption energy induces lower OER overpotential. Consequently, adsorption energy of (Li2O)2/Li2O2/LiO2 and desorption energy of Li+/O2 are useful factors for characterizing the catalytic activity. These findings contribute to understand the doping effect on catalysis and provide insights into the screening and design of novel catalyst in Li O2 batteries.

Bimetallic catalyst has attracted considerable attention due to the higher catalytic activity and better stability than monometallic. In this paper, different Au@Ni bimetallic structures decorated graphene oxide were prepared by adjusting the mass ratio of Au and Ni. A novel sensor based on Au@Ni bimetallic heterodimer (Au@Ni-BHD/rGO) or core-shell (Au@Ni-BCS/rGO) structure was constructed for hydrazine oxidation. The electrocatalytic activity was compared and verified by chronoamperometry, amperometry and cyclic voltammetry. Electrocatalytic active surface area was calculated by Randles-Sevick equation. The electrocatalytic performance of Au@Ni-BHD/rGO modified electrode was investigated and exhibited a low oxidation potential (0.07 V) with two wide linear range from 0.2 μM to 1 mM and 1 mM to 9 mM for sensing hydrazine with a low detection limit of 0.06 μM. Likewise, Au@Ni-BCS/rGO modified electrode towards the addition of hydrazine also showed a lower oxidation potential (0 V) with two wide linear range from 3 μM to 1 mM and 1 mM to 20 mM, and a low detection limit of 0.9 μM. Moreover, both of the modified electrodes offered high selectivity, good reproducibility and stability. This study demonstrates a promising sensing material for electrochemical detection of hydrazine and a new idea for the development of other sensors.

Biodegradable materials are of great interest for the development of temporary implants. While most works have focused on Mg-based materials, recently, zinc and zinc based alloys are attracting increasing attention in this field. In this work, large scale area of flower structure zinc oxide nanotube (ZnO NT) layers were manufactured on the surface of pure zinc via anodic oxidation. Surface morphology and composition were characterized with SEM, XRD and XPS. The length of ZnO NTs was approximately 18 μm. Electrochemical tests in SBF solution showed that ZnO NT layers enhanced the electrochemical activity of pure zinc, from the perspective of degradation rate, the Zn/ZnO NT composite is more suitable for bone fixation compared with pure zinc. Immersion tests demonstrate that more Ca/P deposition occurs on the surface of ZnO NT samples, indicating a better biocompatibility compared with pure zinc. In addition, ZnO NTs have a large number of potential applications, such as use for drug release, or based on their catalytic and semiconductive properties.

Although non-toxic solution processing offers a scalable approach for growth of Cu2ZnSnS4 (CZTS) thin films, it must suppress the formation of secondary phases and yield facile conformal large grained films with minimum process steps. While growing CZTS films from environment-friendly ethanol based solutions, here we demonstrate how precursor concentration and post sulfurization critically affect the reaction pathway and morphology of the films. Deposition from lower ionic concentration precursor solution and sulfurization with nominal sulfur amount yielded phase-pure films. However, the thickness and grain size of these films were far lower than that desired for solar cell application, thus necessitating overlay depositions to achieve desired thickness and grain size. This issue was alleviated by increasing the ionic concentration in the precursor solution and the sulfur amount during sulfurization. It was found that coating from 1 M Cu-solution in just two dipping cycles followed by sulfurization at 500 °C yielded phase pure kesterite CZTS films of ~850 nm thickness. In addition, differently with the reported bilayered structure, the films exhibit a uniform microstructure with reasonably large grains. The resulting films showed the bandgap of 1.42 eV and very high photosensitivity upon illumination of white light.

Composites of metal oxide with nanostructured carbons have been pursued intensively to evade issues like low intrinsic electronic conductivity, large irreversible capacity loss (IC), and poor coulombic efficiency (CE) of metal oxides in lithium-ion batteries (LIBs). In this report, we demonstrate one-pot solvothermal synthesis of V2O5 sheets using ethylene glycol and their composite with MWCNT by electrostatic self-assembly. The phase identification and morphological features were evaluated by XRD, FESEM, and HRTEM techniques, whereas structural properties were acquired from FTIR and Raman spectroscopy data. HRTEM of pristine V2O5 clearly confirms the formation of sheet-like morphology with few tens of nanometers thickness. Investigation of both the pristine V2O5 and V2O5/MWCNT composite materials as positive electrode in LIBs, the latter delivers a capacity of 265 mAh g−1 at 0.1C and 180 mAh g−1 at 1C rate which are higher than the performance of former (238 mAh g−1 at 0.1C rate). The improved electrochemical performance of the V2O5/MWCNT composite cathode in terms of specific capacity, coulombic efficiency, and cycle life stability is ascribed to good electronic and ionic conductivity as well as high lithium storage along both sides of basal plane of V2O5 sheets.

A novel polyvinylpyrrolidone biochar@ZnFe2O4/BiOBr heterojunction photocatalyst was successfully prepared by solvothermal method using ethylene glycol as solvent and characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, ultraviolet–visible diffuse reflectance spectroscopy, transient photocurrent responses, and electrochemical impedance spectroscopy. Ciprofloxacin (CIP) was selected as a target pollutant to study the photocatalytic performance of the biochar@ZnFe2O4/BiOBr photocatalyst under visible light irradiation (λ > 420 nm). Results showed that the biochar@ZnFe2O4/BiOBr exhibited better degradation properties for CIP degradation than those of pure BiOBr and BiOBr/ZnFe2O4 composites. The improved photocatalytic performance may be due to the good absorption properties of biochar, effective photogenerated carrier separation, and prolongation of recombination time caused by the ZnFe2O4/BiOBr heterojunction. Novel Here we fabricate a novel biochar@ZnFe2O4/BiOBr Heterostructure for Ciprofloxacin (CIP) degradation under visible light. The BiOBr and ZnFe2O4 served as heterojunctions, which could significantly promote the separation and migration of photo-induced electron-hole pairs. The morphology and photoelectrochemical properties of photocatalysts were explored in detail. The Biochar@ZnFe2O4/BiOBr exhibited excellent photocatalytic activity for CIP degradation. Based on the free radical capture experiment. The main reactive species involved in the degradation process were identified and Inferring the possible photocatalytic mechanism. This study affords a new reference for fabricating highly efficient photocatalysts with synergistic effect and amazing capacity for practical wastewater treatment.

The design and fabrication of novel metal-supported catalysts for energy conversion and heterogeneous catalysis is a pivotal theme. Herein, we present the synthesis of bimetallic palladium nanoalloys supported on halloysite nanotubes, PdM@HNTs, where M = Co, Cu, and Ni and their catalytic performance towards CO oxidation. The synthesis procedure involves simple co-reduction of the metals precursors using NaBH4 on halloysite nanotubes support. The synthesized catalysts retain the tubular morphology of halloysite support with surface area of 90–107 m2 g−1. Transmission electron microscopy (TEM) revealed smaller size for bimetallic nanoparticles (6–8 nm) compared to Pd (14 nm). PdNi displayed the highest catalytic activity towards CO oxidation. Moreover, PdCo and PdNi demonstrated enhanced CO oxidation kinetics compared to PdCu and PdNi as revealed from the calculated activation energies. DFT calculations revealed that the order of catalytic activity is PdNi > PdCo > PdCu > Pd which is in agreement with the experimental results and that the adsorption energy of CO2 on the different catalysts has no apparent role in the whole activity of the catalyst. In conclusion, PdM@HNTs catalysts expressed homogeneous distribution for metallic nanoparticles as well as high dispersion and expressed promising potential to be applied in real flare control processes. This work was made possible by NPRP Grant no. NPRP 8-1912-1-354 from the Qatar National Research Fund (a member of the Qatar Foundation). The statements made herein are solely the responsibility of the authors. Appendix A Scopus

Designing of cost-effective electrocatalysts for efficient oxygen evolution reaction (OER) is highly desired for the practical production of clean hydrogen energy. Herein, reduced graphene oxide (RGO) supported N-doped porous carbon-coated NiFe alloy composite (NiFe@NC/RGO) was synthesized via a facile pyrolysis route. The introduction of RGO effectively protects the active NiFe component from agglomeration and largely promotes charge transfer. Meanwhile, the formation of porous N-doped carbon shell provides sufficient contact between active species and electrolyte, thus exposing plenty of accessible active sites. Specifically, the optimized NiFe@NC/RGO composite shows superior electrocatalytic performance, delivering an overpotential as low as 223 mV at current density of 10 mA cm−2, and a small Tafel slope of 48.7 mV dec−1 in 1 M KOH solution, which outperforms commercial precious metal oxide catalysts such as RuO2 and a vast majority of electrocatalysts reported so far. Long-term cycling test demonstrates that the overpotential at current density of 10 mA cm−2 has almost no change after 1000 cycles at a scan rate of 50 mV s−1, indicating its quite good stability. The low-cost and high-performance electrocatalyst developed in this work shows great potential for practical hydrogen production from electrolysis of water.

Reliable and accurate detection of blood glucose level is extremely important to monitor and prevent diabetic complications. Transition metal oxides, especially copper oxide (CuO), hold great potential for glucose sensor due to their good electrochemical activity and controllable structure. Herein, we fabricated a facile non-enzymatic sensor using CuO microtubes (MTs) as electrocatalytic active materials for electrochemical detection of glucose. The CuO MTs were hydrothermally prepared via the Kirkendall effect of KCu7S4 microwires. The obtained CuO shows unique tubular structure with abundant nanosheets on the surface and exhibits good crystallinity. The developed CuO based sensor exhibits a wide linear range up to 5.664 mM, with a satisfactory sensitivity of 992.073 μAcm−2 mM−1 and a short response time within 2 s. The detection limit for glucose is as low as 307 nM. In addition, the sensor also displays superior anti-interference performance, excellent reproducibility and long-term stability owing to its special tubular structure. All these excellent results show that the prepared CuO MTs can be a promising electrode material for glucose sensing.

In order to improve the photocatalytic activity of nano-TiO2 and achieve its recovery, TiO2/MS-SiO2 photocatalyst is prepared when TiO2 nanoparticles are distributed on the surface of amorphous SiO2 microspheres (MS-SiO2) through sol-gel method, and its composition and morphology structure are characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and transmission electron microscopy (TEM). Besides, the photocatalytic properties are tested and evaluated by degradation efficiency of methyl orange under ultraviolet light. The results show that TiO2 nanoparticles uniformly dispersed on the surface of MS-SiO2 and combined with MS-SiO2 strongly by Ti-O-Si bond, whereas TiO2 is anatase crystal and grain size is about 5 nm. Under ultraviolet light for 90 min, the degradation rate of TiO2/MS-SiO2 for methyl orange reached 100%, which is better than pure TiO2 and P25. In addition, photocatalytic performance remains unchanged in a cyclic experiment. Transmission and separation efficiency of nano-TiO2 photo-generated charge carriers is improved by loading on the surface of MS-SiO2 so that MS-SiO2 can enhance the photocatalytic performance of pure TiO2. Moreover, this fact is illustrated by electron paramagnetic resonance intuitively.

Nanogels with ordered structures have attracted extraordinary attention for biomedical applications. Among the preparations of hierarchical nanogels, the fabrication of Janus nanocarriers is an important branch. In this study, a two-faced magnetite structure has been constructed from a thermosensitive terpolymer i.e. N-isopropylacrylamide-co-acrylamide-co-allylamine (NIPAAm-co-AAm-co-AA) terpolymer and hydrophobic polymer i.e. PCL, through solvent evaporation from emulsion droplets (SEED) technique. The amphiphilic copolymers with Janus morphology were prepared from click reaction between PCL and terpolymer and in order to fix this morphology, the PCL chains tails of clicked adduct were tied together by magnetite nanoparticles. Moreover, to evaluate the potential of this prototype sharp-shaped nanogel in drug delivery, the comparative core-shell structure was nano-engineered via a challengeable emulsion method! The prepared polymers and their Janus and core-shell nanogels were fully characterized by various methods.

The combination of silicon and carbon layer exhibited superior lithium capacity and rate performance, however, the corresponding lithiation mechanism in atomic scale is not clear. In this work, the electrochemical performance of silicon anode incorporated with carbon layer is evaluated by first principles calculations. The average length of Li Si bond near the silicon‑carbon interface is significantly shorter than that in silicon, indicating an irreversible capacity loss. The reversible lithium capacity is then calculated by excluding the lithium atoms with shorter Li Si bonds. A reversible capacity of 2197 mAhg−1 is predicted and is comparable to the reversible capacity of 2509 mAhg−1 in experiment. Moreover, the silicon‑carbon structure corresponds to enhanced electronic conductivity and lithium diffusion coefficient compared to silicon, resulting in excellent rate capability as revealed in experiments.

Rechargeable aqueous zinc-ion battery is a promising energy storage device because of its low cost and high safety. However, they are still in their infancy due to the limited choice of cathodes with high capacity and satisfactory cycling performance. In this work, porous V2O5 materials were obtained by pyrolysis of vanadium-MOF and adopted as intercalation cathode for aqueous zinc-ion batteries. V2O5 purchased commercially as a control, the effects of specific surface area, pore size distribution and mixed valence of electrodes on the performance of batteries were studied. The novel cathode delivers high capacities of 300 mA h g−1 compared to 60 mAh g−1 for C-V2O5 at current density of 100 mA g−1. The energy density of this Zn ion battery is about 230 Wh kg−1, which is much higher than commercial lead acid batteries. The capacity of P-V2O5 electrode retains 120 mA h g−1 even at 2000 mA g−1, which is much higher than that of C-V2O5. Moreover, the structure of V2O5 nanoplates and their composites with carbon materials can improve the cyclic stability.

Stainless steel wire mesh/bismuth oxybromide (BiOBr) were synthesized as immobilized photocatalysts. The effects of conductive wire mesh substrate and calcination on the photocatalytic performance were investigated. The morphology, crystal structure, composition, and optical properties of hierarchical wire mesh/BiOBr photocatalyst were investigated. The degradation of 99% dye can be achieved within 50 min by S250 photocatalyst which was calcined at 250 °C. The recycled photocatalyst also shows good stability. The activity of the immobilized photocatalysts was enhanced by increasing the surface area (flower-like texture of BiOBr), facilitating separation of photogenerated charge carriers (good contact between BiOBr and conductive stainless steel wire mesh), and improving the crystal properties (facet effect, dominant (001) facets by calcination). This study provides a way to optimizing the activity of immobilized photocatalysts for the treatment of hazardous pollutants in wastewater.

A new composite gel polymer electrolyte (PEO-Bp-LATP) membrane consisting of poly-ethylene oxide (PEO), benzophenone (Bp) and varying amounts of highly ion-conducting lithium aluminum titanium phosphate (LATP) particles was prepared by significant Ultraviolet (UV) technology. The as-prepared PEO-Bp-LATP electrolyte membranes showed improved mechanical properties and superior electrochemical performances in Lithium metal batteries (LMBs). Typically, PEO-Bp-15 wt% LATP showed highest ionic conductivity (σ = 3.3 × 10−3 S.cm−1) at RT, a high Li-transference (tLi+ = 0.77 ) and wider electrochemical stability window (ESW) above 5 V as well as good mechanical strength (9.3 MPa). More significantly, the PEO-Bp-15 wt% LATP membrane has an excellent inhibitory effect on Li dendrite expansion in Li symmetric cells and presents a long term cyclic stability with current density of 2 mA/cm2 over 1100 h for Li//PEO-Bp-15 wt% LATP //Li. Our results for the measurement of galvanostatic charge-discharge deliver fascinating rate performance at 0.1C. Hence, the present study demonstrates that the UV-irradiated PEO-Bp-LATP membrane can be a promising electrolyte to meet the requirements for the next-generation LMBs.

In this study, CoMnFeO4 ternary metal oxide nanoparticles are prepared via hydrothermal and sol-gel ignition methods. Their structures are investigated and characterized by FT-IR, XRD, XPS, BET, SEM, EDX and HR-TEM analysis. Also, magnetic properties of nanoparticles synthesized by two methods are compared on a vibrant sample magnetometer (VSM) with maximum saturation magnetization values found to be 28.83 emu g−1 and 23.17 emu g−1, respectively. SEM and HR-TEM results reveal that the mean particles size of hydrothermally synthesized (about 25 nm) nanoparticles is smaller and more uniform than that of their counterparts synthesized by sol-gel ignition method (about 65 nm). Their supercapacitor behaviors are studied and compared by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) methods. The hydrothermally synthesized sample shows higher specific capacitance of about 770 F g−1 (at 1 A g−1) in 3 M KOH while this value for the sample synthesized by sol-gel ignition approach is about 150 F g−1. The higher specific capacitance can be attributed to smaller particle size, more electroactive sites due to higher specific surface area, and quantum size effects. Also, some initial mechanistic studies are performed to achieve a deeper insight into the electrochemical behavior of the nanoparticles implying that the oxidation-reduction process of nanoparticles is generally quasi-reversible and diffusion-controlled. So, by considering the higher performance, the hydrothermal approach developed here is beneficial from cost, time and environmental points of view.

Wettability patterns have significant application potential in liquid transportation and water collection. Plasma hydrophilization is high-efficient and less-destructive, and has been widely used for preparing wettability patterns. However, the plasma-treated surfaces tend to recover to its original wettability, causing invalidation of the patterns. As a green treatment method, boiled water treatment could construct nanostructures, which is favorable for hydrophilicity-retaining; while the hydrophilization effect of plasma treatment would promote the reaction. Therefore, it should be possible to combine plasma and boiled water treatments to prepare long-lasting wettability patterns. In this paper, superhydrophobic aluminum surfaces were modified by plasma jet followed by boiled water treatment. The time stability, microstructures and chemical compositions of the treated surfaces were investigated by testing contact angles, scanning electron microscope, X-ray diffractometer, and X-ray photoelectron spectroscopy. The surfaces treated by plasma jet and boiled water could retain superhydrophilicity for a long time under various storage conditions, including normal ambient, high temperature or high humidity. On the basis of this technique, long-lasting patterns could be prepared on different metal substrates. The green method proposed is expected to have promising application potential in fabricating wettability patterns and lab-on-chip devices, especially for those used in severe conditions.

In this work we present a multifunctional filter having polyacrylonitrile (PAN) nanofibers with embedded commercial P25 and/or TiO 2 bead filler. The composite nanofibers were synthesized through a green method of electrospinning. The properties of the filters having single- and/or binary-filler composite fibers were investigated. It was found that TiO 2 beads have higher electrostatic attraction to capture PM2.5 than P25. Binary-filler nanofiber filter having a higher beads/P25 ratio shows an excellent filtration efficiency of 96.75% with a low pressure drop of 88 Pa. As a result, a high quality factor of 0.039 has been obtained. This is 177% enhancement as compared to the PAN-only filter. Furthermore, the composite filters also exhibit antibacterial activity of 5.5 under 30 min UV irradiation, which is 9 times higher than that of the PAN-only filter. These results indicate that PAN-based composite filter with commercial P25 and/or TiO 2 beads fillers is excellent material for making facial mask.

Stable and efficient separation of oil slicks from oil-contaminated water in harsh environments is still a big challenge. Recently, three-dimensional hydrophobic/super-oleophilic materials exhibit promising application in continuous oil/water separation. Herein, we developed a facial method to prepare three-dimensional super-hydrophobic/super-oleophilic carbon fiber felt (CFF) materials by anchoring the hydrophobic Fe3O4 nanoparticles onto 3D CFF. Owing to the well-defined micro-/nano-structure and low surface energy, as-obtained CFF materials showed high water contact angle of 164.1 ± 1.3° and low oil contact angle of 0°. As a result, as-prepared CFF materials exhibited excellent adsorption driven by external magnetic field and continuous oils separation from immiscible oil/water mixtures, with the high separation efficiency up to 99.99%. More importantly, the resulting super-wetting material showed stable super-hydrophobic property and continuous oil/water separation performance in harsh environments such as strong corrosive/salt solutions, organic solvents, and high/low-temperature systems. Therefore, this work provides an alternative strategy to obtain 3D super-hydrophobic/super-oleophilic materials with easy operation, durable and efficient continuous oil/water separation performance, exhibiting potential application for treating the large-scale industrial oily wastewater in harsh environments.

This study provides insights into the charge transfer and solar light photocatalytic activity induced by the synergistic effect between defect state and plasmon in Au nanoparticle-decorated hierarchical 3D porous ZnO microspheres. Photoluminescence emission shows that the photogenerated electrons of ZnO are efficiently transferred from its defect level to the conduction band (CB) induced through the coupling action of the defect state and plasmon. Compared with the pure ZnO microsphere photocatalysts, the fabricated Au/ZnO microsphere photocatalysts show remarkably enhanced activity for the decomposition of methylene blue dyes under solar-light illumination. Moreover, the photocatalytic performance of the Au/ZnO microspheres was manipulated by tuning the size of the Au nanoparticles (NPs). When decorated with 10 nm Au NPs, the Au/ZnO microsphere photocatalyst achieves a rate constant of 0.09846 min−1, 26 and 8.5 times higher than those of the pure ZnO microsphere photocatalysts (0.00378 min−1) and the Au/ZnO microsphere photocatalysts decorated with 30 nm Au NPs (0.01154 min−1), respectively.. The enhanced photocatalytic performance of the Au/ZnO microsphere photocatalysts is ascribed to the defect state-plasmon coupling-induced efficient transfer of photogenerated electrons from the defect level to the CB of ZnO. This work enhances the understanding of the defect state-plasmon coupling-induced enhanced photocatalytic activity in metal/semiconductor heterostructure photocatalysts.

Hole-conductor-free carbon-based perovskite solar cells (C-PSCs) are known for their low-cost and superstability. In this work, different mesoporous structures, namely, mesoporous TiO2 + Al2O3 (mp-TiO2 + Al2O3), mp-TiO2 + ZrO2, mp-Al2O3, mp-TiO2, and blocking compact layer of TiO2 (bl-TiO2), were investigated and systematically compared. Results revealed that the performance of PSCs with double-layer mesoporous structure was better than that of the other mesoporous structures, especially PSC with the structure of mp-TiO2 + Al2O3 obtained the open-circuit voltage (Voc) of 0.97 V and the current density (Jsc) of 23.77 mA cm−2, respectively, the photoelectric conversion efficiency (PCE) reached 11.3% because of the function of the mesoporous layer in separating TiO2 and carbon, thereby avoiding direct contact and reducing the leakage of the current. Al2O3 and ZrO2 are insulating materials that could effectively prevent electrons from transmitting back to C. The mesoporous structure of the device based on mp-TiO2 + Al2O3 was evenly distributed, the perovskite crystal particles based on mp-TiO2 + Al2O3 were enlarged, uniform, and relatively tight, and the grain boundaries between the perovskite crystal particles were remarkably reduced. Among the films, the perovskite film of mp-TiO2 + Al2O3 structure had the highest absorption intensity. This study provided a new basis for commercializing low-cost PSCs.

Silver-nanoparticles (Ag-NPs) supported over protonated graphitic-carbon nitride (pg-C3N4) for photocatalytic CO2 reduction in different reforming processes have been investigated. The Ag-NPs/pg-C3N4 samples, prepared by a combined ultrasonic-dispersion and photo-deposition process, were tested for photocatalytic CO2 reduction by H2O, steam reforming of methane (SRM), dry reforming of methane (DRM) and bi-reforming of methane (BRM). Pure g-C3N4 was favourable for CO evolution, while pg-C3N4 promoted both H2 and CH3OH production. Similarly, yield of CO over 5 wt% Ag/pg-C3N4 was 2.5 times more than CO over the pg-C3N4 and 5.2 times higher than for the g-C3N4 catalyst. This enhancement was evidently due to faster charge separation because of protonation and Ag-loading. More interestingly, performance of photocatalyst was entirely different when using different reforming systems. Enhanced photoactivity was achieved in BRM process compared to SRM and DRM process during efficient utilization of charge carriers. The highest QY was achieved for CO, H2 and CH3OH production during BRM process. This revealed that photocatalytic BRM is a promising approach for the production of CH3OH, CO and H2 in a single step. The results of this study fully demonstrate superiority of Ag/pg-C3N4 nanosheets for the development of photocatalytic dry/bi-reforming of methane systems for renewable fuels production.

The influence of the processing conditions on the interfacial and electrical properties of the high-k/SiGe gate stacks based on ozone oxidation is investigated. Detailed analyses of the relationship between the interface chemical structures and the corresponding electrical properties, as a function of oxidation time, reveal that the change in the distribution of the Ge atoms is the dominant factor to achieve superior electrical properties. In addition, the increase in the ratio of Si 4+ to Si 3+ of the oxide interlayer can help decrease the interface trap densities. These results provide us an important passivation route for the high-k/SiGe interface based on ozone oxidation, which is to explore an oxidation method that can realize an ultrathin interlayer including as much Si 4+ component as possible over a long oxidation time.