Search

A Ni-based metal organic framework (Ni-BDC) and subsequently derived NiFe-LDH were studied to overcome the defect of the low availability of active sites for the oxygen evolution reaction (OER) during the water splitting process. This work reported NiFe-LDH nanosheets with an ultra-thin structure through an in situ surface-conversion derived from Ni-BDC. The unique structure and characteristic morphology were confirmed using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy, and the OER activities of the catalysts were systematically studied. The obtained results indicated that the synthesized Ni-BDC@NiFe-LDH-2 showed excellent OER activity, with a low overpotential of 272 mV at a current density of 10 mA cm−2, a small Tafel slope of 45 mV dec−1, and excellent stability, owing to the addition of abundant metal sites and the expansion of the electron transport channels during the conversion process to form the ultra-thin layer structure. This work provides a novel strategy for the application, design, and manufacture of metal organic framework (MOF)-based high-efficiency active materials.

Lightweight, broadband microwave absorbing materials, with strong absorption capacities, are an urgent demand for practical applications. The microstructural and microwave absorption properties of LaFeO3 samples prepared by a sol-gel method using different amounts of Sr are investigated systematically. X-ray diffraction and Rietveld refinement studies showed that Sr2+ doping can distort the crystal structure of LaFeO3, leading to lattice expansion and spin tilt of the Fe-O-Fe bond angle. The improvement of magnetic properties mainly originates from the synergistic effect of the bond angle spin tilt and crystal structure defects. Oxygen vacancies will be generated due to the fluctuations in the valence state of Fe3+ resulting from the substitution of La3+ by Sr2+ as deduced from the X-ray photoelectron spectroscopy analysis. The generation of oxygen vacancies, electronic hopping and polarization loss may be one of the main reasons for changes in the electromagnetic parameters. The minimum reflection loss (RL) of La1–xSrxFeO3 nanoparticles with the Sr doping of 0.2 can reach approximately -39.3 dB at 10 GHz for the thickness of 2.2 mm, and the effective absorption bandwidth (RL ≤ -10 dB) can reach approximately 2.56 GHz. In addition, the La1–xSrxFeO3 nanoparticles also can obtain better microwave absorbing performance in the C-band (4–8 GHz) with the minimum RL of -36.8 dB for the matching thickness of 3.0 mm and Sr content of 0.3. Consequently, La1–xSrxFeO3 nanoparticles are promising materials for use in a high-performance and adjustable electromagnetic wave absorber, particularly in C-band and X-band.

Walnut shell, a renewable and easy-accessible agricultural biowaste, was utilized as a precursor for the preparation of activated carbon materials with KOH activation in this study. After a series of activation processes, therefore, the activated carbon derived from walnut shells achieved a specific surface area of 1016.4 m2/g. With the advantage of low cost and environmental friendly, the prepared carbon materials have superior electrochemical performance and excellent prospects in the application of supercapacitor electrodes. The morphology and textural properties of the AC samples were examined by N2 adsorption–desorption, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and FTIR spectra. All the electrode samples exhibited excellent electrochemical performance. The AC-650 electrode achieved a maximum specific capacitance of 169.2 F/g at current density of 0.5 A/g in 6 M KOH electrolyte. This work provided an effective approach for the treatment and utilization of agricultural biowastes, which was worthwhile for economic, environmental, and societal viewpoints.

The Zn-doped LiNi1/3Co1/3Mn1/3O2 samples were prepared by a simple sol–gel method combined with calcination at certain temperature. The crystal structure, morphology, and lithium storage performance of as-prepared materials were studied by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and galvanostatic charge/discharge tests. The Zn-doped samples kept same structure as that of LiNi1/3Co1/3Mn1/3O2 and took on morphology of nanoirregular cubes with length of 50–200 nm. The electrochemical performances for the Zn-doped LiNi1/3Co1/3Mn1/3O2 were improved obviously. Especially, the sample doped with 6% Zn (LNCM-0.06Zn) behaved with higher reversible capacity and better cycle performances (It maintained reversible capacity as 173 mAh g−1 after 100 cycles at 0.5 C and 118 mAh g−1 after 500 cycles, even at high rate of 8 C). So LiNi1/3Co1/3Mn1/3O2 doped with suitable amount of Zn is a promising cathode for lithium-ion battery application.

Vacancies engineering was widely reported as the promising strategy for the improvement of the photocatalytic performance of semiconductor photocatalysts. In current work, carbon vacancies are constructed successfully in graphitic carbon nitride (g-C3N4) photocatalyst via magnesium vapor etching. Experimental results show that the formed carbon vacancies in g-C3N4 photocatalyst can significantly improve the photocatalytic H2 generation performance. XRD, FTIR, SEM/TEM, XPS and PL characterization data are employed to evidence the construction of carbon vacancies, which are revealed to be the reason for the enhancement of photocatalytic H2 evolution. This work develops an alternative route to construct carbon vacancies in g-C3N4 materials and gives an insight into the influence of vacancies on the photocatalytic performance of photocatalysts.

The developments of inexpensive and efficient oxygen evolution reaction (OER) electrocatalysts without noble metals are very critical for energy conversion and storage systems. In this work, a series of NiCo-layered double hydroxide (NiCo-LDH) and NiCo oxides using co-precipitation and thermal treatment method have been successfully synthesized. Structural characterizations have been investigated by X-ray powder diffraction (XRD), Field emission scanning electron microscope (FE-SEM) equipped with energy-dispersive X-ray mapping technology (EDS), Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy respectively (XPS). By intercalating and eliminating CO33− anions in the layers of bulk NiCo-layered double hydroxide (NiCo-LDH), the as-present catalyst (NiCo–CH) exhibit remarkable advantages for OER performance, including porous nanostructures, high surface area, high content of Ni3+ and Co2+ on the surface and abundant active sites. With these favorable features, NiCo–CH shows a much better OER performance than that of other catalysts and commercial Pt/C, which has a low onset potential (1.51 V), a low overpotential (343 mV at 10mA/cm−2) and a small Tafel slope (66mV/dec−1). Our work presents an effective strategy to controllably design and synthesize NiCo-LDH electrocatalysts with optimizable OER performances.

In this paper, Bi2O3 samples were prepared by a hydrothermal way. The effects of microstructure on the electrochemical properties of Bi2O3 samples were studied by adjusting hydrothermal time of synthesization (2, 6, 10, 14, and 18 h) to control the microstructure. The structure, morphology, specific surface, and chemical environment of Bi2O3 were characterized by XRD, SEM, BET, and XPS. XRD patterns revealed that all diffraction peaks intensity increased with the increase of reaction time and it indicates that a higher crystallization had taken place. However, continuous improvements in electrochemical properties of the samples were not found with enhancement of the crystallinity. The specific capacitance decreases with the increase of crystalline grain size. From the SEM results, as the hydrothermal time increases, it is obvious that the sample particles agglomerate to flakes and then to flowers. The sample of Bi2O3 with a hydrothermal time of 10 h exhibited a high specific capacitance (980 F g−1 at 1 A g−1), excellent capacity retention (86.9% from 1 to 20 A g−1), and a good cycle stability (85.2% at 5 A g−1 after 1000 cycles). The significance of this work is that it is possible to boost the electrochemical properties of the samples by controlling the microstructures, including reducing the crystalline grain size and maintaining a proper morphology of Bi2O3 particles.

Ag–Carbon–TiO2 composite tubes were prepared by using polystyrene/AgNO3 composite fibers as a sacrifice template and a co-pyrolysis process. The Ag–Carbon–TiO2 tubes were characterized by SEM, TEM, X-ray diffraction, Raman spectrum, XPS, and UV–vis spectrum. The results showed that the Ag–Carbon–TiO2 tubes possessed uniform tubular structure with amorphous carbon, graphitic carbon, and Ag nanoparticles (AgNPs) distributing uniformly in TiO2. The Ag–Carbon–TiO2 tubes were confirmed high UV–vis light utilization and photocatalytic degradation efficiency to Rhodamine B due to the carbon doping, the surface plasmon resonance of AgNPs and the tubular structure, and the degradation of Rhodamine B reached 90% in 6 h. Meanwhile, they showed an excellent antibacterial effect on staphylococcus aureus, and the fatality rate of Ag–Carbon–TiO2 tubes to staphylococcus aureus reached 99.9% in 24 h when its concentration was higher than 4 mg/ml. The co-pyrolysis process could repress the AgNPs to grow to be large particles, which could be a key for the excellent antibacterial property. The research showed a promising strategy for preparing Ag–Carbon–TiO2 composite tubes by co-pyrolysis of PS composite electrospinning fibers, indicating their potential application in wastewater treatment and antibacterial materials.

The two-dimension RGO (reduced graphene oxide)-NiS 2 dual co-catalyst synergistic modified g-C 3 N 4 nanosheets aerogel is synthesized via the continuous thermal oxidation etching-hydrothermal method-freeze drying process. The results of scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) imply that the RGO-NiS 2 dual co-catalyst is introduced into the aerogel system successfully. The photocatalytic activity of the RGO-NiS 2 synergistic modified g-C 3 N 4 aerogel remarkably exhibits an enhancement of 67 times than that of simplicial g-C 3 N 4 . Further, the photocatalytic process and the mechanism of the photocatalytic hydrogen production enhancement are studied, which is ascribed to RGO-NiS 2 dual co-catalyst synergistic modification, including the Pt-like behavior of the NiS 2 and the high conductivity and large specific surface area of the RGO.

Hematite nanowires (NWs) and nanoblades (NBs) were successfully synthesized by thermal oxidation at 400 °C and 600 °C, respectively, under atmospheric conditions. Ion implantation was performed using a homemade metal vapor vacuum arc (MEVVA) technique as a new method to interfere with the growth mechanism of NWs/NBs. The metal, rare earth and gas ions with high energies were implanted into the NWs/NBs. The structure and morphology of NWs and NBs were systematically analyzed using different methods such as X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, scanning electron microscopy (SEM). The NWs became short and bend, which showed a large deformation and the surface energy changed after Ni/Co/Er/Ar ion implantation. The implanted NWs/NBs were covered entirely by an oxide layer after a short annealing time and new NWs/NBs regrew during a long annealing time. The results were indicated that both the NW and NB formation mechanisms were ascribed to the tip growth model, where the diffusion played a key role. What’ more, the influence of ion implantation on growth mechanism of α-Fe2O3 NWs/NBs was independent of implanted ion species, implanted energy and dose and damage extent decided solely by defects.

A series of Cu-doped ZnO (Cu-ZnO) photocatalysts have been synthesized by a simple hydrothermal method. X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy (UV–vis DRS), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) confirmed that Cu ions have been effectively incorporated into the ZnO lattice, and as the doped Cu amounts increased to 1.5%, the Cu2O will be formed. Under the effect of Cu ions and the Cu2O/ZnO heterojunction, the prepared 1.5% Cu-ZnO nanocomposites exhibited superior catalytic activity in photodegradation of Rhodamine B (RhB) dye under UV light irradiation. RhB could be degraded 99.9% after the irradiation time of 21 min. The photodegradation rate constant achieved 0.2429 min−1, which was 2 times than that of pure ZnO. The results of photoluminescence (PL) and photoacoustics (PA) spectroscopy studies indicated that the recombination efficiency of photogenerated electrons and holes was decreased for 1.5% Cu-ZnO nanocomposites as compared to that of samples. The surface photovoltage (SPV) and the transient photovoltage (TPV) measurements directly demonstrated that separation efficiency was improved, and the recombination time of electrons and holes in 1.5% Cu-ZnO nanocomposites was prolonged due to the synergistic effect of the impurity level and p-n heterojunction. Finally, the possible mechanism is proposed to illuminate the photogenerated charge behavior under UV light irradiation，and the roles of doped Cu and precipitated Cu2O in the photodegradation process were discussed. This work opens a novel avenue to preparing the metal doping photocatalysts with efficiently charge separation and charge transfer.

Semiconducting metal oxides (SMO) have been investigated as important gas sensing materials for detecting various inflammable and toxic gases; however most of them are suffered from low response and high operation temperature. Ultrathin SnO2 nanosheets with dominant high-energy {001} facets were synthesized by a facile hydrothermal method, and the gas sensing properties to formaldehyde (HCHO) were systemically studied. The structure, morphology, specific surface area, band gap and chemical state of the ultrathin SnO2 nanosheets were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), N2 adsorption–desorption, UV–Vis diffuse reflectance spectrum and X-ray photoelectron spectroscopy (XPS), respectively. Sensors based on SnO2 nanosheets show outstanding gas sensing properties to HCHO vapor at the optimum operating temperature (OOT) of 200 °C. The nanosheet sensor exhibit a response of 207.7 to 200 ppm HCHO at 200 °C with the response-recovery time of 30 s and 57 s, respectively. Notably, as low as 1 ppm HCHO can be readily detected with a high response value (Sr = 6.1). The excellent HCHO sensing performance is mainly originated from the structural sensitization of large specific surface area, characteristically small thickness and dominant high-energy {001} facets.

MoO3, as a potential electrode material in energy storage, has recently been attracted increasing attention in supercapacitor. However, due to the poor electrical conductivity of MoO3, its practical application is limited. In this work, the electronic conductivity and the electrochemical performances of MoO3 electrode have been improved by introducing carbon on the surface of MoO3 nanobelt. The novel C@MoO3 nanocomposite was successfully prepared by hydrothermal in this study. The as-prepared samples were characterized by XRD, Raman, Fourier transform infrared, X-ray photoelectron spectroscopy, scanning electron microscope and transmission electron microscope. The electrochemical measurement results showed that the C@MoO3 nanocomposite exhibits superior electrochemical properties. The specific capacitance of C@MoO3 is 179 F g− 1 at current density of 1 A g− 1, which is 2.8 times than MoO3 at the same current density. The outstanding electrochemical performance could be attributed to these reasons including the advantages of the synergistic effect and good conductivity of carbon layer. This work will facilitate the application of other transition metal oxides with similar structures in energy storage.

The construction of oxygen vacancies, as one of defects engineering, is a promising strategy to boost the electrocatalytic activity. Herein, CuO nanoflakes enriched with oxygen vacancies were successfully synthesised via a simple one-pot method with stirring. High-angle annular dark-field scanning, X-ray photoelectron spectroscopy and electron spin resonance spectroscopy were performed to confirm the existence of enriched oxygen vacancies. The as-synthesised CuO nanoflakes enriched with oxygen vacancies and exhibited an excellent performance for glucose detection with a lower onset-potential of +0.22 V, ultrahigh sensitivity of 4870 μA mM−1 cm−2 and low detection limit of 0.5 μM. The superior performance of the CuO nanoflakes may be attributed to surface oxygen vacancies, which accelerate the adsorbed hydroxyl ions to promote the formation of Cu3+ species, thereby, reducing the one-potential and facilitating the glucose oxidation. This work would serve the guide for the rational design of other efficient catalysts for glucose detection via constructing oxygen vacancies.

X-ray photoelectron spectroscopy (XPS) is an efficient technique for recognizing the state of elements. However, the effects of X-ray irradiation on change in the chemical state are sometimes ignored, which may impair the understanding of the environmental behavior of these elements. This study determined the change in the U 4f spectra induced by X-ray irradiation during XPS detection. For U(VI) on non-semiconductors, X-ray irradiation led to a negative shift of U 4f7/2 to ∼ 380.8 eV due to the break of the uranyl molecules, but not resulting in U(IV) species. However, owing to the photocatalytic reduction of U(VI), the irradiation of U(VI) loaded semiconductors rapidly induced the negative shift of U 4f7/2 peak to ∼ 379.8 eV, which is the characteristic of U(IV). Moreover, apparent photo-reduction occurred even if the samples were far from the center of the X-ray beam (>3971 μm). Based on these findings, methods for reducing potential error due to X-ray irradiation are suggested, including using the minimum scan time, measuring uranium-containing samples first or independent of other samples, and using X-ray of lower intensity. The results indicated that X-ray induced alteration to the chemical states must be considered when using X-ray techniques.

The amino-functionalized metal organic framework (NH2-Cu-MOF) was fabricated via bottom-up synthesis strategy. Detailed characterization using electron microscopy, X-ray photoelectron spectroscopy and atomic force microscopy demonstrated that the as-synthesized NH2-Cu-MOF was two-dimensional nanosheet (a thin thickness ∼4.2 nm). Results showed that the as-synthesized NH2-Cu-MOF nanosheet possessed fluorescence property (λem = 425 nm) as well as peroxidase mimic activity. On the basis of these two properties, we proposed a biosensor for hypoxanthine detection. The fluorescence intensity had a linear relationship with the hypoxanthine concentration in the range of 10–2000 μM. The limit of detection was 3.93 μM (S/N = 3). This work contributes to the synthesis of a new two-dimensional MOF nanosheet and extends the application of two-dimensional MOF nanosheet on biological luminescent sensors.

Zinc-doped indium oxide (IZO) film, as an important transparent conductive oxide, has attracted increasing attention in various scientific and engineering areas. In the present work, discharge-voltage and reactive-oxygen controlled IZO films were grown by magnetron sputtering and studied systematically. The microstructure, element distribution and chemical bonding of IZO films were investigated by X-Ray diffraction (XRD), transmission electron microscope (TEM), Energy Dispersive X-Ray Spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The optical and electrical properties of IZO films were studied by controlled oxygen and discharge voltage. The typical microstructure of IZO films with optimal optical and electric properties has been characterized. High discharge voltage and matched oxygen vacancies could promote the low resistivity of IZO films, which could be determined by the electronic concentration and mobility.

Glycosyl-functionalized metal organic framework-5 (Glycosyl/MOF-5) based porous carbon nanofibers (Glycosyl/MOF-5-CNFs) were synthesized using MOF-5 as a precursor and glucose as an additional carbon source. The cubic Glycosyl/MOF-5 nanoparticles and polyacrylonitrile suspensions were used to prepare nanofibers by using electrospinning. The as-prepared electrospun nanofibers were then carbonized at high temperatures under argon to prepare Glycosyl/MOF-5-CNFs. The obtained material was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption-desorption isotherms, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The electrochemical behavior of quercetin was studied using a glassy carbon electrode modified with Glycosyl/MOF-5-CNFs. Further, the influences of the modifier dosage, enrichment potential, enrichment time, and pH were investigated. Under optimal conditions, the linear responses for quercetin were in the ranges of 2.0 × 10−7–1.0 × 10−5 mol L − 1 and 1.0 × 10−5–2.0 × 10−4 mol L − 1 with a detection limit of 8.33 × 10−8 mol L − 1. The fabricated electrochemical sensor was successfully utilized for the determination of quercetin, with recoveries obtained between 95.5% and 100.2%.

Pyrochlore is considered as the most promising catalytic materials for its open structure and readily tuning characteristics by doping appropriate ions. In this paper, we report a simple and efficient sol-gel method to synthesizeY2Ru1.9Mn0.1O7-δ and Y2Ru1.9Fe0.1O7-δ to promote oxygen evolution. It was found that the introduction of Mn/Fe into YRO enhanced the catalytic activity. Through qualitative and quantitative analysis of oxygen vacancies by means of XPS and TG, a mass of oxygen vacancies wasintroducedin the pyrochlore structure due to exotic Mn and Fe, which act as active sites to promote catalytic performance. Subsequent stability tests found that the doped Fe ions significantly increased the stability of the structure while Mn ions are inverse. To further investigate the activity of Y2Ru1.9Mn0.1O7-δ and Y2Ru1.9Fe0.1O7-δ, the first principles calculation was used. It indicates that the lower the oxygen vacancy formation energy, the better the catalytic activity. In light of the improvement of Y2Ru1.9Fe0.1O7-δ stabilty, the first-principles calculation results show that it is due to the Fe ion presence increased the surface dissolution energy and strengthen the covalence between Ru–O of the matrix, which effectively inhibiting the exsolution of Ru.

The carrier concentration of the indium tin oxide (ITO) thin films can be enhanced by supplying extra conducting electrons with tin dopants. However, defects and impurities, which are rich around grain boundaries, result in strong carrier scattering. In this work, ITO films prepared by magnetron sputtering were subjected to supercritical carbon dioxide (SCCO2) fluid treatment with different concentrations of InCl3 solutions, In3+ ions were introduced in the grain boundaries for the purpose of regulating defects and impurities there. The photoelectric performance of ITO films was improved significantly after the SCCO2 fluid treatments, which was interpreted for the effects of SCCO2 on as-deposited ITO microstructures based on the experimental results of X-ray photoelectron spectroscopy and positron annihilation lifetime spectroscopy. Upon the SCCO2 fluid treatment, the dehydration effect passivated the dangling bonds around the grain boundaries, meanwhile, the indium ions diffused into the grain boundaries, resulting in the formation of ITO-like lattice structure there.

With the ever-increasing oil spillages, oil-water separation has attracted widespread concern in recent years. In this work, a nature-inspired polyphenol method has been developed to fabricate the durable superhydrophobic surfaces for the oil-water separation. Inspiring from the adhesion of polyphenol and reducing capacity of free catechol/pyrogallol groups in polyphenol, firstly, the simple immersion of commercial materials (melamine sponge, PET, and nonwoven cotton fabrics) in tannic acid (TA) solution allows to form a multifunctional coating on the surface of sponge or fabrics, which was used as reducing reagent to generate Ag nanoparticles (NPs). Then, decoration of 1H, 1H, 2H, 2H-perfluorodecanethiol (PFDT) molecules produced superhydrophobic surfaces. The surface topological structure, chemical composition, and superhydrophobic property of the as-prepared surface are characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS), and water contact angle (WCA) measurements. The WCAs of as-prepared sponge and fabrics were higher than 150°. The stability, absorption capacity, and recyclability of as-prepared sponge and fabrics were investigated. The as-prepared sponge demonstrates high oil/water selectivity and high absorption capacity (66–150 g/g) for a broad variety of oils and organic solvents, and was chemically resistant, robust against abrasion, and long-term durability in harsh environments. Most important of all, it can continuously separate various kinds of oils or organic pollutants from the surface of water. This study presents a facile strategy to fabricate superhydrophobic materials for continuous oil-water separation, displaying great potential in large-scale practical application.

In this paper, mesoporous Cu2O–CeO2 nanospheres were fabricated via a facile, low-temperature solution route in the presence of poly(2-vinylpyridine)-b-poly(ethylene Oxide) (P2VP-b-PEO) block copolymers. The prepared mesoporous Cu2O–CeO2 nanospheres were characterized systematically by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and nitrogen adsorption/desorption. The formation mechanism of mesoporous Cu2O–CeO2 nanospheres was discussed. The results show that the molar ratios of Ce3+/Cu2+ and the reaction time have an important influence on the nanostructure of Cu2O–CeO2 composite spheres. The resultant Cu2O–CeO2 nanospheres exhibit superior catalytic activities in the reduction of 4-nitrophenol to 4-aminophenol by NaBH4. The activity factor (K = k/m) for the Cu2O–CeO2 nanospheres prepared with the molar ratio of Ce3+/Cu2+ of 5/1 is 3006.6 s−1 g−1, which is much higher than reported values. This paper demonstrates a highly controllable approach to the production of mesoporous Cu2O–CeO2 nanospheres, which have potential applications in the areas of catalysis, adsorption, sensors and so on.

Lithium-sulfur batteries are promising electrochemical energy storage devices because of their high theoretical specific capacity and energy density. An ideal sulfur host should possess high conductivity and embrace the physical confinement or strong chemisorption to dramatically suppress the polysulfide dissolution. Herein, uniform TiN hollow nanospheres with an average diameter of ~160 nm have been reported as highly efficient lithium polysulfide reservoirs for high-performance lithium-sulfur batteries. Combining the high conductivity and chemical trapping of lithium polysulfides, the obtained S/TiN cathode of 70 wt.% sulfur content in the composite delivered an excellent long-life cycling performance at 0.5C and 1.0C over 300 cycles. More importantly, a stable capacity of 710.4 mAh·g−1 could be maintained even after 100 cycles at 0.2C with a high sulfur loading of 3.6 mg·cm−1. The nature of the interactions between TiN and lithium polysulfide species was investigated by X-ray photoelectron spectroscopy studies. Theoretical calculations were also carried out and the results revealed a strong binding between TiN and the lithium polysulfide species. It is expected that this class of conductive and polar materials would pave a new way for the high-energy lithium-sulfur batteries in the future.

A series of epoxy resin (EP) composite coatings reinforced with functionalized cubic boron nitride (FC-BN) and functionalized hexagonal boron nitride (FH-BN) were fabricated successfully on 316L stainless steel by hand lay-up technique. The structure properties were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The morphologies were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Moreover, UMT-3 tribometer and surface profiler were used to investigate tribological behaviors of as-prepared composite coatings under dry friction and seawater conditions respectively. The results demonstrated that the presence of FC-BN or FH-BN fillers could greatly decrease the friction coefficient (COF) and wear rate of epoxy, in addition, composite coatings possess better tribological properties under seawater condition which was attributed to the lubricating effect of seawater. Moreover, FC-BN endows the composite coatings the highest wear resistance, and FH-BN /EP composite coatings exhibited the best friction reduction performance which is attributed to the self-lubricating performance of lamella structure for FH-BN sheet.

In this study, superhydrophobic and UV-blocking silk fabrics are fabricated via one-step in-situ synthesis of zinc oxide (ZnO) nanorods on silk fabrics and further n-octadecanethiol (ODT) modification process. The surface composition, morphology, and wettability of modified silk fabrics are characterized by X-ray diffraction (XRD), X-ray photoelectron spectrometer (XPS), field-emission scanning electron microscopy (FE-SEM), and water contact angle (WCA). The as-prepared silk fabric exhibits superhydrophobic performance (WCA >150°) and excellent anti-UV ability (UPF over 50). The obtained superhydrophobic surface shows excellent mechanical and chemical stability. The as-prepared multifunctional silk fabrics will be used in advanced protective textiles and self-cleaning fields.

Traditional reactive gas O2 was replaced by CO2 to fabricate carbon-doped tin oxide (SnOx-C) using pulse direct current magnetron sputtering (pDC-MS) with different Ar/CO2 flow ratios, the physical and electrochemical properties of SnOx-C films were characterized by X-ray reflection (XRR), X-ray photoelectron spectroscopy (XPS), battery tester, et al. The results showed that CO2 gas would be decomposed into C and O atoms by Ar+ bombardment, the sputtered Sn particles were oxidized by O atoms and the C atoms were introduced simultaneously in the form of interstitial atoms. All properties of the films changed orderly with the increase of CO2 flow ratios and the sputtering atmosphere of Ar/CO2 = 18/12 corresponded to one turning point, moreover, the films deposited with high CO2 flow ratios (CO2 ≥ 12 sccm) showed an improved cycle performance contrasted with the films deposited with low CO2 flow ratios (CO2 ≤ 7 sccm) or the pure SnOx films without carbon-doped. The composition of SnO1.64-C film with the maximum carbon content of 6.1% was obtained by the sputtering condition of Ar/CO2 = 15/15, it possessed an extra capacity of ~80 mAh/g compared with that of SnOx film and delivered a stable discharge capacity of 483.3 mAh/g, retention rate of 77.7% in the 50th cycle at a constant current density of 44 μA/cm2.

In the present work, two-dimension lamellar Ti 3 C 2 was employed as additive of LiNa 2 AlH 6 . Volumetric dehydrogenation results informed that the onset dehydrogenation temperature of the ball milled LiNa 2 AlH 6 + 5 wt% Ti 3 C 2 sample was lowered by 68 K from that of pristine LiNa 2 AlH 6 . Isothermal pressure-composition (P-C-I) curves and van't Hoff plots demonstrated that the dehydrogenation enthalpy value (61 kJ mol H 2 −1 ) of LiNa 2 AlH 6 + 5 wt% Ti 3 C 2 was significantly reduced from the pristine LiNa 2 AlH 6 (68 kJ mol H 2 −1 ). By means of XPS analyses, it can be revealed that the destabilization of LiNa 2 AlH 6 should be resulted from the involvement of Ti and the yield of unidentified Ti 3+ species. Furthermore, it can be concluded that the lowering of dehydrogenation temperature was merely due to the thermal destabilization of LiNa 2 AlH 6 by Ti 3 C 2 , since Ti 3 C 2 hardly improved the dehydrogenation kinetics of LiNa 2 AlH 6 and reduced its activation energy. However, hydrogenation kinetics was slightly enhanced from the released products of LiNa 2 AlH 6 + 5 wt% Ti 3 C 2 .

Hollow structure LiNb3O8 photocatalysts were prepared by a hydrothermal method assisting sintering process. The particles’ aggregation to form hollow structures with obvious cavities can be attributed to the Li element volatilization during calcination process. All the LiNb3O8 powders show high photocatalytic efficiency of degradation of methylene blue (MB), especially for the sample calcined at 700 °C (LNO700), with only 3 h to completely decompose MB. The photo-degradation of MB follows the pseudo-first-order kinetics, and the obtained first-order rate is 0.97/h. The larger degradation rate of LNO700 can be attributed to its hollow structure which provides a larger specific surface area and more active sites to degrade the MB molecules. The cycling test of photo-degradation and adsorption of MB over LNO700 powder indicates that the hollow structure of the LiNb3O8 photocatalyst is stable and the LiNb3O8 photocatalyst is an efficient photocatalyst with good reusability, confirmed by the XRD and X-ray photoelectron spectroscopy tests before and after photo-degradation of MB.

In this work, pure m-Bi2O4, Bi4O7 and m-Bi2O4/Bi4O7 heterojunction photocatalysts with improved visible-light-driven photocatalytic performance have been successfully fabricated by a facile one-pot hydrothermal method. With the prolongation of hydrothermal reaction time, m-Bi2O4 microrods gradually transform into Bi4O7 microsheets and m-Bi2O4 can be in-situ grown on the surface of Bi4O7, resulting in an intimate interface. The phase structure, morphology, microstructure, surface chemical state and optical property are characterized by X-ray powder diffraction (XRD), Fourier transform-infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–visible diffuse reflectance spectroscopy (UV–vis DRS) and X-ray photoelectron spectroscopy (XPS). In comparison with pure m-Bi2O4 and Bi4O7, the optimized m-Bi2O4/Bi4O7 composite photocatalysts show higher visible-light-driven photocatalytic performance toward RhB. In view of electronic energy-band structure analysis, photoelectrochemical and photoluminescence spectra (PL) results, we contribute the improved performance to synergetic effects between m-Bi2O4 and Bi4O7 in the composite followed a possible S-scheme heterojunction photocatalytic reaction mechanism, which prolongs pathway and suppress the recombination rate of photogenerated carriers. Furthermore, the mechanism of effect of m-Bi2O4/Bi4O7 mass ratio and geometry architecture on photocatalytic behavior is also investigated in this paper. Our work offers a new insight to design and develop high-active phase-transition induced bismuth mixed-valence surface heterojunction photocatalyst with facile preparation.

Recently, the influence of polar facets on the gas sensing performance of metal oxides has drawn much attention, yet the facet-dependent gas sensing properties of rare earth oxides have not been reported so far. In this work, taking CeO2 as an example, uniform single-crystalline nanopolyhedra, nanorods and nanocubes of cubic CeO2 were selectively prepared by a hydrothermal method at different temperatures and NaOH concentrations, using Ce(NO3)3 as the cerium source. According to X-ray powder diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) analysis, these CeO2 nanocrystals possess different exposed crystal planes: {111} and {100} for nanopolyhedra, {110} and {100} for nanorods, and {100} for nanocubes. Abundant defects were confirmed on the surface of three CeO2 nanocrystals by X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) and photoluminescence (PL). Notably, gas sensors based on these three CeO2 nanocrystals exhibited distinct response values towards dimethylamine vapor in the following order: nanocubes > nanorods > nanopolyhedra, while excluding the effects of characteristic dimension and specific surface area. The response order of CeO2 nanocrystals is primarily ascribed to the different content of surface defects and {100} polar facets instead of {111} and {110} nonpolar facets.

Pd nanoparticles (PdNPs) with the diameter of ∼3.2 nm were successfully confined within a robust three dimensional (3D) N-doped porous graphene (R3DNG) via a polyol-assisted reduction strategy. The as-obtained PdNPs/R3DNG composite was characterized by SEM, TEM, XRD and XPS, and was conducted as electrocatalyst for methanol oxidation in alkaline medium. The results showed that PdNPs/R3DNG featured the remarkable electrocatalytic activity (2.71 A mg −1 Pd) and outstanding cyclic stability (66.5% forward peak current retention after 1000 cycles), which is even superior to the state-of-the-art Pt/C catalyst. The synergistic effect between the support of R3DNG and PdNPs is believed to be responsible for the outstanding electrocatalytic performance.

Using polystyrene spheres and EO20PO70EO20 as double templates, a three-dimensionally ordered macroporous (3DOM) CeO2-ZrO2 material was synthesized by the sol–gel method combined with the decompression filling method. The composition, structure, morphology, and surface physicochemical properties of the material were characterized by XRD, XPS, UV–vis/DRS, SEM, TEM, HR-TEM, and N2 adsorption–desorption measurements. The results show that the material has a good crystal structure with neat and ordered macroporous multilayered, open, and transparent structure and a clear shape of the dendritic crosslinking. Moreover, the walls of the material are formed by accumulating smaller particles, thus improving the light absorption efficiency. The unique morphology of 3DOM CeO2-ZrO2 significantly increased its activity during the multimode photocatalytic experiments. In the photocatalytic hydrogen evolution experiment, 3DOM CeO2-ZrO2 showed a stronger ability of water splitting into hydrogen. This indicates the dendritic crosslinked 3DOM CeO2-ZrO2 can simultaneously enhance the photodegradation and photolysis of water.

The role of oxygen defects and dopants of Cu and N on ferromagnetism is discussed in undoped, N-doped, Cu-doped and Cu/N-codoped anatase TiO2 nanotube-arrays fabricated by two-step anodization method. X-ray photoelectron spectroscopy shows the presence of Cu2+ and/or Cu+ in the distorted octahedral coordination of TiO2. The UV–vis absorption spectra and photoluminescence spectra reveal the presence of oxygen defect related the peaks of absorption and emission in Cu-doped and Cu/N codoped-TiO2. Room temperature ferromagnetism is observed in all the TiO2 nanotubes. The saturation magnetizations for those specimens decreases in the order of Cu-doped, undoped, Cu/N-codoped and N-doped samples, which are in consistent with the results of the first-principles calculations based on density-functional theory. It is speculated that both oxygen vacancies and Cu d-states are involved in the ferromagnetism. Spin polarization occurs by the formation of bound magnetic polaron between electrons in Cu+/Cu2+ d-states and the unpaired spins in oxygen vacancies.

This work studied the electrodeposition of aluminum (Al) coating on uranium (U) substrate from aluminum chloride (AlCl3)-1-ethyl-3-methylimidazolium chloride (EMIC) ionic liquid at room temperature. The coating was characterized by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The adhesion between the coating and U substrate was estimated by thermal shock test. The corrosion resistance of the coating was evaluated by open circuit potential and potentiodynamic polarization testing in 3.5 wt.% NaCl solution. Results indicated that anodic etching of U in AlCl3-EMIC ionic liquid favored the adhesion of Al coating to U substrate by complete removal of the oxide on U surface. The inter-diffusion between Al and U at the interface was also observed. A uniform, compact and smooth coating was obtained at the current density of 20 mA/cm2. The Al coating significantly enhanced the corrosion resistance of U by reducing the corrosion current density by one order of magnitude.

Poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) and poly(N,N′-dimethyl-(methylmethacryloyl ethyl) ammonium propanesulfonate) (PDMAPS) were grafted on polyurethane (PU) surfaces by one-pot ATRP and click chemistry in order to improve the lubricating and antifouling properties. The successful grafting of PMPC and PDMAPS was confirmed by X-ray photoelectron spectroscopy. The immobilization of zwitterionic polymer brushes significantly improved the surface hydrophilicity and lubricating property of PU. In addition, the protein and bacteria adsorption on the modified PU surfaces were reduced greatly due to the presence of hydrated layer around the zwitterionic groups. The present surface modification approach was simple and versatile for functionalization of polymer surfaces.

The structures and compositions of CaTiO3 samples synthesized by solid state, sol–gel, and hydrothermal methods were characterized by various means such as X-ray diffractometer, scanning electron microscope, Brunauer–Emmett–Teller, Fourier transform infrared spectrometer, Raman spectra, X-ray photoelectron spectroscopy, and UV–vis diffuse reflection spectra. Photocatalytic activity of CaTiO3 was investigated via measuring the photodegradation of methylene blue. As-prepared samples by three methods were orthorhombic CaTiO3, showing heterogeneous sizes and diverse morphologies. Functional groups including Ti–O, N–O, and OH were detected for three CaTiO3 samples. In particular, the XPS spectra suggested the presence of Ti–O–N or Ti–N–O structure in CaTiO3 lattice, indicating that N in air or Ca(NO3)2·4H2O (Ca source) may lead to forming N-doped CaTiO3 by solid state method or sol–gel and hydrothermal methods. Photocatalytic activity of CaTiO3 prepared by the hydrothermal method was the highest among three CaTiO3 samples, whereas it was lower than that of TiO2.

In this paper, titanium dioxide supported by multi-walled carbon nanotubes (MWCNTs/TiO2), and Mn doped TiO2 supported by MWCNTs (MWCNTs/Mn-TiO2) were synthesized in a sol–gel method. Characterizations of these two prepared photocatalysts were analyzed by means of transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and UV–vis diffuse reflectance spectra (DRS). The results show that MWCNTs and Mn dopants inhibits the grain growth of TiO2. The excellent optical properties in UV and visible region were both observed on 0.5% MWCNTs/Mn-TiO2. The photocatalytic oxidation and removal efficiency of SO2 from simulated flue gas were investigated experimentally in a fix-bed reactor. Removal efficiency of SO2 can reach 69% while using 0.5% MWCNTs/Mn-TiO2 as photocatalysts at the optimal conditions (155 mg/m3 SO2, 8% O2, 5% H2O). The desulfurization efficiency was lower in the presence of NO due to the competition for adsorption sites between SO2 and NO. O2 and H2O played important roles in the photocatalytic oxidation of SO2. In addition, the possible reaction mechanism involved was also proposed here.

In this paper, a three-dimensional ordered hollow sphere (3DOH) structure composite Pt/TiO2-ZrO2 was prepared by using polystyrene (PS) colloidal spheres as the template and combining with two-step vacuum impregnation method, of which the composition, crystalline structure, morphology, and surface physicochemical properties were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance (UV-vis/DRS), photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and nitrogen adsorption-desorption measurements. The results illustrate the crystal type of 3DOH Pt/TiO2-ZrO2 is mainly anatase TiO2 and tetragonal ZrO2 phase, which exhibits a three-dimensional ordered hollow sphere structure. Hollow spheres are arranged orderly; moreover, the composite shows a strong absorption in the visible region due to the effect of surface plasmon absorption (SPA) after doping Pt nanoparticles. Meanwhile, the photocatalytic activity of 3DOH Pt/TiO2-ZrO2 was investigated by using Congo red as the model molecule. The results show that 3DOH Pt/TiO2-ZrO2 has good photocatalytic activity under multi-modes photocatalytic experiments, and its activity is higher than that of P25, ZrO2, and other Pt/TiO2-ZrO2 not treated by PS colloidal spheres. In addition, the total amount of hydrogen production of 3DOH Pt/TiO2-ZrO2 is 100 times as much as the commercial P25 in the photocatalytic hydrogen evolution experiment (8 h), which shows an excellent photolysis of water hydrogen production activity.

A graphene oxide-based nano-metal composite oxide CuFe2O4/GO was successfully prepared by a versatile self-assembly approach. Structure and morphological characterization of CuFe2O4/GO nanocomposite were studied in detail by a series of characterization techniques including XRD, FT-IR, XPS, BET, SEM, and TEM. The results revealed that the self-assembly process did not destroy the composition and morphology of the spinel-structured CuFe2O4 particle, and the transparent GO sheets with wrinkled and rough texture are tightly coated on the surface of CuFe2O4 nanoparticles like a layer of thin gauze clothing. The particle size of CuFe2O4 is about 200 nm. Catalytic activity of as-prepared CuFe2O4/GO nanocomposite on the thermal decomposition of cyclotrimethylene trinitramine (RDX) was investigated via differential scanning calorimetry (DSC). The experimental results show that the CuFe2O4/GO nanocomposite has much higher catalytic activity than single CuFe2O4 nanoparticles and GO. Thermal decomposition temperature and apparent activation energy of RDX were reduced from 241.27 to 220.34 °C and from 172.6 to 142.56 kJ mol−1, respectively. The improved performance could be attributed to the “positive synergistic effect” between CuFe2O4 nanoparticles and GO.

A variety of Ce-Fe solid solutions was synthesized by a microwave hydrothermal method following the molar ratio of Fe and Ce in Bayan Obo rare earth concentrate, to evaluate the catalytic action of Fe and Ce in NH3-SCR denitrification reaction. The microstructure, surface properties and catalytic activity of CeO2-Fe2O3/Al2O3 catalyst samples were characterized by NH3-SCR, SEM, BET, NH3-TPD, XRD, Raman, XPS, and DRIFTS. The results showed that the adsorption capacity of NH3 is the strongest when the molar ratio of Ce-Fe was 1:0.35, and the catalytic activity is the highest, up to 90%. The increase of iron species is beneficial to the denitration performance of the catalysts. The structure of CeO2 is distorted to form the Ce-Fe solid solutions, and more oxygen vacancies in the catalysts were exposed. Activated nitrate was generated from NO under the action of Ce3+and Fe2+, which was converted to N2 and H2O with the amide.

In this paper, hydrothermal method has been employed to synthesize oxygen-modified carbon dots (O-CDs) from citric acid and nitrogen and sulfur modified carbon dots (N,S-CDs) from citric acid and cysteine. Both as-prepared carbon dots achieve naked-eye observable blue-green luminescence. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) are used to exhibit the chemical composition of carbon dots. The structure and size of both carbon dots are similar via transmission electron microscopy (TEM) and dynamic light scattering (DLS), which indicates that the function of size effect can be neglected in this study. Fluorescence properties, UV-vis absorption and solubility are systemically studied to investigate the influence of surface modification. The N,S-CDs show high quantum yield and excitation independent photoluminescence, however, the O-CDs present low quantum yield and excitation dependent photoluminescence, and both carbon dots achieve strong photo-stability. The cytotoxicity of carbon dots is also performed on U87-MG brain tumor cells, which shows that both carbon dots process good biocompatibility and low toxicity in live cell. The bright cellular imaging photos indicate that both carbon dots have great potential to serve as high quality optical imaging probes.

Graphene oxide is modified by diethylenetriamine through a one-step route to prepare GO-NH(CH 2 ) 2 NH(CH 2 ) 2 NH 2 (GO-DETA), which has primary and secondary amino groups and carboxyl groups. GO-DETA is characterized by Fourier transform-infrared spectrum (FT-IR), X-ray diffraction spectroscopy (XRD), thermo-gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The catalytic performance of obtained GO-DETA is investigated in Knoevenagel condensation and Michael addition in water; the results show it can be used as an efficient and stable catalyst. In addition, it has other features, such as simple preparation, good recyclability and environmental friendliness.

Herein, we reported a Z-scheme 0D/2D Ag6Si2O7/CN composite photocatalyst via simple precipitation method, where the electron structure and optical properties of Ag6Si2O7 and CN materials were studied by theoretical computation. The XPS, TEM, radical trapping experiments and ESR measurement results illustrated the formation of the Z-scheme 0D/2D Ag6Si2O7/CN heterostructure. The crystal structure and surface composition of the prepared materials were characterized by XRD, SEM and FT-IR. The UV–vis DRS, PL, I-t, and EIS demonstrated that all composites have improved light absorption ability and enhanced photo-generated charge separation rate. The construction of 0D/2D Ag6Si2O7/CN Z-scheme heterojunction is helpful to improve photodegradation ability, which can not only enhance the separation and transmission efficiency of the photogenerated carriers, but also retain the strong redox ability of photocatalysts. This paper provides a novel comprehension of the mechanism of Z-scheme composites by combining theoretical calculations and experiments.

Facile construction of multifunctional fabrics with durability still remains a challenge in the past decade. In this work, we report a facile fabrication of non-fluorinated superhydrophobic and antibacterial cotton fabric surfaces via in situ growing zeolitic imidazolate framework-8 (ZIF-8) nanocrystals on cotton fibers under room temperature condition and subsequently coating with polydimethylsiloxane (PDMS). The surface morphology and chemical composition of treated fabric have been characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction analysis (XRD) and X-ray photoelectron spectroscopy (XPS). The as-prepared cotton fabric showed superhydrophobic property with a water contact angle (WCA) of 151.36° and a sliding angle of 3.6° and excellent antibacterial properties against E. coli and S. aureus. The durability of the superhydrophobic and antibacterial fabrics was evaluated by repeated washing and abrasion cycles. The as-prepared fabrics retained their excellent antibacterial property and superhydrophobicity after 300 cycles of abrasion and 5 cycles of washing. The robustness of superhydrophobicity and antibacterial activity made this method has wild application prospects in biomedical field in the future.

Biomaterial polyacrylamide (PAM) hydrogel was first studied for self-healing coatings of Mg alloys. In this work, a PAM gel with Ce4+ inhibitor was in-situ composited on the surface of micro-arc oxidation treated AZ31 Mg alloy. The results indicated that the scratched samples with the composite coating could avoid pitting corrosions and self-heal in neutral salt spray test (NSST). XPS and SEM-EDS analysis reveal that the self-healing performance was ascribable to the inhibition of Ce4+ and the bridge adsorption of PAM gels. Moreover, the results of open circuit potential and polarization curve indicate that the self-healing product film has good corrosion resistance.

Here, the micropatterned gold nanoparticles (AuNPs) on graphene oxide (GO) nanosheet (AuNPs@GO) was fabricated via thiol-Michael addition click reaction under ultraviolet (UV) light. First, AuNPs and GO were both functionalized by acrylamide and dithiothreitol, respectively, which were characterized by transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS) and ultraviolet–visible spectroscopy (UV–vis). The size of acrylamide modified AuNPs increased to 52.8 ± 16.5 nm compared to bare AuNPs (44.1 ± 14.5 nm). The AuNPs@GO could be fabricated under the UV-light, and the UV–vis signal varied depending on the concentration of AuNPs. Also, the micropatterned structure of AuNPs@GO nanosheet was accomplished by using a designed mask, which showed a high potential for cancer diagnosis and therapy.

In the current study, in situ free radical polymerization was employed to prepare Cu2+-imprinted composite hydrogel (Cu2+-ICH). The cross-sectional morphology of the Cu2+-ICH evaluated by scanning electron microscopy indicated that the copper-loaded Cu2+-ICH became rougher and the pore size of the gel became smaller compared to the unloaded Cu2+-ICH. The ability of the Cu2+-ICH to adsorb Cu2+ from aqueous solutions was assessed using batch adsorption technique. The adsorption capacity increased with the initial concentration of Cu2+, but decreased as the temperature rose from 298 to 318 K. Thermodynamic parameters such as Gibbs free energy (ΔG 0), enthalpy (ΔH 0), and entropy (ΔS 0) for the Cu2+ adsorption were evaluated. It was suggested that the adsorption process was a spontaneous, exothermic process that had positive entropy. Selectivity study indicated that ion imprinting technique resulted in excellent affinity of the Cu2+-ICH toward Cu2+. Finally, the adsorption mechanism was studied by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The results indicated that copper adsorption was mainly through interactions with the amine and carbonyl groups.

The nanocomposite nc-ZrCN/a-CNx films with a carbon content varying from 34 to 61 at.% were deposited by filtered cathodic vacuum arc technique (FCVA) under different C2H2/N2 reactive gas flows. The effect of different carbon contents on compositional, nanostructural characteristics of nanocomposite nc-ZrCN/a-CNx films was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscope (TEM), Raman scattering spectroscopy (Raman) and X-ray photoelectron spectroscopy (XPS). Results showed that nanocomposite nc-ZrCN/a-CNx films were composed of about 8 nm sized ZrCN nanocrystalline embedded in different amount of a-CNx amorphous matrix. Mechanical properties of nanocomposite nc-ZrCN/a-CNx films showed a significant dependency on thickness of a-CNx matrix. Nanocomposite nc-ZrCN/a-CNx film reached the highest hardness (41 GPa) and reduced modulus (320 GPa) when the thickness of a-CNx matrix was around 0.4 nm. Nanocomposite nc-ZrCN/a-CNx film at higher carbon content has lower friction coefficient (0.2) and better wear resistance. The nanocomposite films possess lower Icorr and higher Rp values than the single phase film.

Acetylene blacks were oxidized with nitric acid to obtain some insight into the mechanism of oxidative degradation in sealed condition. Changes in the morphologies and structures of acetylene blacks in the course of oxidation were investigated using transmission electron microscopy, X-ray diffraction, Raman, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and nitrogen adsorption and desorption isotherms. Time-dependent experiments were carried out to investigate the degree of oxidation. It was found that, with the increase of acid steaming duration ranging from 2, 4, 6 to 8 h, the yield of oxidized product decreases from 87.5%, 64.4%, 51.0% to 27.5%. Experimental results demonstrated that the prolonged treatment led to an increased hollow ratio and an enhanced degree of oxidation. The functionalized hollow sample was characterized and it was observed a well developed microporous and mesoporous structure.

In present work, the effect of dielectric barrier discharge (DBD) plasma on Pd/ZnO catalytic CO2 conversion under various discharge powers is investigated. An obviously enhanced CO2 conversion from 17.1% to 32.5% with the increasing of Pd content at 30 W can be observed. Catalyst microstructures with the presence of ZnO reduction were characterized by x-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), x-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (H2-TPR) and CO chemisorption. Moreover, plasma-excited CO2 temperature-programmed desorption (P-CO2-TPD) was carried out to reveal the changing of plasma excited CO2 activation on Pd/ZnO. Accordingly, Pd promoted ZnO reduction was found to influence both the amount and strength of CO2 activation with the presence of plasma, which therefore leads to a higher plasma-catalytic performance for CO2 conversion. Highlights •In DBD reactors, plasma excited CO2 activation plays a vital role for CO2 conversion. •Pd promoted ZnO reduction can influence both the amount and strength of CO2 activation under plasma. •Plasma-excited CO2 temperature-programmed desorption is used to reveal the changing of CO2 activation on Pd/ZnO.