Search

Tm3+ doped SnO2 semiconductor thin films were prepared by RF magnetron sputtering method. The doping effects of rare-earth thulium on the crystal structures, optical properties, chemical compositions, surface morphologies of tin-oxide thin films, together with the electrical properties of the corresponding SnTmO thin film transistors (TFTs), were investigated. SnTmO semiconductor thin films with polycrystalline structures feature a wide bandgap of over 3.8 eV. XPS results reveal the typical photoelectron signals of Sn4+ and Tm3+. Smaller crystallite size and more grain boundaries can be formed in doped SnO2 samples which may be responsible for the degradation of device mobility. It was found that the electrical properties of SnO2 TFTs can be modulated by Tm3+ incorporation. The appropriate Tm3+ doping concentration is around 1.6 at.% within our experimental conditions. The optimized field-effect mobility, subthreshold swing, threshold voltage, on-off current ratio and the interface trap density are 5.5 cm2 V−1 s−1, 0.618 Vdec−1, −2.3 V, 5 × 107 and 6.7 × 1011 cm−2, respectively. Stability measurements show threshold voltage shifts of 12.3 V and −11.7 V in PBS and NBS process respectively. This study may provide useful understandings on rare-earth doped SnO2 semiconductors.

Blending of plant-based cellulose and marine-derived chitosan in micro-level has potential to make fascinating materials. However, this task is frequently hindered by the poor solubility of the polysaccharides. Here, using a green alkali/urea solvent media together with a well-designed dissolving strategy, original cellulose pulp and chitosan power were dispersed into a homogeneous solution. Driven by the intermolecular hydrogen-bond interaction, cellulose and chitosan chains were facially self-assembled into a unique 3D alloy structure. Owing to the rich interface interactions, the tensile strength and breaking elongation of the alloy film increased by 69% and 260%, respectively, when compared to a pure chitosan film. Besides, the 3D alloy films with a pore diameter of 920–1435 nm exhibited an extremely high cell viability which was higher than 95%. Additionally, accelerated wound healing rate of 95.6% reached in the presence of the alloy film after two weeks using a full-thickness wound in a rat model.

Bi2MoO6 quantum dot (QDs-BM)/Bi2MoO6 nanosheet (N-BM) homojunction materials were fabricated by a simple method. Under visible light irradiation, the material exhibits significantly enhanced performance in the synergistic removal of heavy metal Cr(VI) and organic dye (RBY). This can be attributed to the fact that the formation of a homojunction because of energy level difference between QDs-BM and N-BM. It boosts the transferring and separation efficiency of electrons and holes, thereby improving the photocatalytic performance of the material. In addition, compared to the removal of a single heavy metal Cr(VI) contaminant, the mixing of an appropriate amount of organic dye (RBY) greatly increases the reduction efficiency of Cr(VI), and the organic dye is also completely degraded. The results of XPS proved that Cr(VI) is completely reduced to Cr(III). The results also show that the synergistic effect of the oxidation of organic pollutants and the reduction of heavy metals effectively increases the photocatalytic performance of the entire system. This is of great significance for the treatment of industrial wastewater containing heavy metals and organic pollutants.

A series of palygorskite-supported manganese oxide (MnOx/PG) catalysts were prepared by a precipitation method using different manganese precursor. The as-prepared MnOx/PG catalysts were used to evaluate the catalytic oxidation of HCHO and characterized by BET, XRD, TG, Raman spectroscopy, TEM, H2-TPR, XPS, and chemical titration. The results showed that the crystalline phase, distribution and Mn valence states of MnOx on the surface of PG depended on the precursors. Birnessite-type manganese oxide (δ-MnO2) formed and uniformly coated on the surface of PG when potassium permanganate (PP) was used as the precursor. The MnOx/PG-PP catalyst showed the best catalytic activity for HCHO removal at low temperature among these catalysts and achieved complete HCHO conversion at 150 °C. More importantly, the dynamic single-pass removal efficiency of MnOx/PG-PP catalyst for ppm-level HCHO oxidation was as high as 95% under high GHSV (300 L/g·h) at ambient temperature. MnOx/PG-PP catalyst also exhibited excellent cycling stability and long-term activity at low and ambient temperature. The kinetic results of MnOx/PG-PP catalyst showed that the oxidation of HCHO followed the Mars-van Krevelen mechanism. The possible reaction pathway of HCHO oxidation was proposed based on in situ DRIFTS and TPSR studies. The large specific surface area, highly distributed active component, a high proportion of Mn4+ species, and lattice oxygen content are responsible for the high catalytic activity of MnOx/PG-PP for oxidation of formaldehyde. This work developed a natural mineral supported manganese oxide as an inexpensive and efficient catalyst for the purification of HCHO in industrial or indoor air environment.

Effective specific recognition of bovine serum albumin (BSA) was accomplished by the thermo-sensitive imprinted microspheres composed of N-isopropylacrylamide (NIPAM), methacrylic acid (MAA) and N,N-methylenebisacrylamide (MBA). These imprinted microspheres were prepared in the presence of hollow Fe3O4 microspheres as substrates via surface molecular imprinting technique (MIT) and grafting copolymerization method. In the imprinting system, hollow Fe3O4 microspheres possessed the distinctive properties of excellent water dispersibility, light weight and high specific surface area. These potential benefits not only reduced the agglomeration of imprinted microspheres, but also increased the effective imprinting area for BSA. And owing to the existence of poly-(N-isopropylacrylamide) (pNIPAM), the fabricated molecularly imprinted polymers (MIPs) were highly sensitive to ambient temperature and played a significant role in efficient recognition for BSA. When treated at 32 °C, the optimal adsorption capacity (Q) and imprinting factor (IF) for BSA were obtained, 430.67 mg/g and 2.01, respectively. Combining hollow Fe3O4 microspheres with thermo-sensitive polymers, the surface-imprinted materials for specific capture of target protein would show great promise for bioseparation and biosensors.

Multi-functionalized magnetic graphene was prepared by surface-initiated initiators for continuous activator regeneration atom transfer radical polymerization (ICAR ATRP) mediated by polydopamine chemistry. The obtained multi-functionalized magnetic graphene was used as an adsorbent for application in adsorption and speciation of arsenic. Adsorption kinetics and isotherms of arsenic were investigated by batch adsorption experiments. The adsorbent displayed simultaneous or selective removal ability for As(III) and As(V) within different pH ranges. The adsorption of both As(III) and As(V) agreed well with the Freundlich isotherm model, and they were effectively adsorbed through chelation and electrostatic interaction, respectively. Moreover, the functionalized magnetic graphene was examined as a column packing material for speciation analysis of arsenic using solid phase extraction technique. As(III) and As(V) could be effectively separated through a sequential elution strategy. An alkaline solution was firstly employed to selectively elute As(V), and then an acidic solution was utilized to elute As(III). The developed adsorbent in the present study was successfully applied to the determination of As(III) and As(V) in natural and environmental water samples with satisfactory results.

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.

The lack of biological activity of pure titanium as a dental implant has attracted increasing attention. This condition can be improved by preparing a layer of nano-hydroxyapatite (nano-HA) coating that is stable and does not easily fall off, which however, remains a challenge. Here, we report the preparation of nano-HA crystals on calcified titanium oxide (TiO2) nanotube arrays by means of anodization, heat treatment, calcification in vacuum and hydrothermal phosphorylation, achieving the chemical bonding between the nano-HA coating and TiO2 substrate. The mechanism of coating formation was also investigated. The results confirmed that annealing at 450 °C could convert the amorphous nanotubes to the anatase structure. Calcium titanate (CaTiO3) was formed on the surface of nanotubes by heat treatment after calcification, which could provide nucleation sites for the formation of nano-HA. Needle-like nano-HA crystals were subsequently formed on the surface of the TiO2 nanotube arrays. The scratch test showed that the adhesion strength between the formed nano-HA coating and the TiO2 nanotube arrays was higher than 29.17 ± 1.07 N. In vitro cell proliferation and adhesion experiments showed that the nano-HA coating had good biocompatibility. Alkaline phosphatase (ALP) activity and osteocalcin (OCN) expressions highlighted the higher osteoconductivity of the nano-HA coating on the surface of TiO2 nanotube arrays compared to the pure Ti.

The combination of carbon and iron oxide has recently attracted increasing research interest in energy conversion and storage. Here, the hybrid nanostructure with N, S-codoped Fe3O4 supported/embedded on/in N-doped porous carbon (NS-Fe3O4@N-PC) nanococoon was prepared via direct pyrolysis of core@shell β-FeOOH@Polypyrrole (β-FeOOH@PPy) composite. Benefiting from the synergistic effect of high redox activity of NS-Fe3O4 and excellent electrical conductivity as well as good mechanical stability of N-PC, the obtained NS-Fe3O4@N-PC exhibited an enhanced specific capacitance of 866 F/g at 1 A/g along with excellent rate capability (383 F/g at 10 A/g) and improved cycling stability (78.2% of initial capacitance retained after 5000 cycles test) while applied as electrode materials of supercapacitor. Significantly, the asymmetric supercapacitor devices assembled using NS-Fe3O4@N-PC as anodes and commercial carbon nanotubes as cathodes can achieve a large stack energy density of 38.9 Wh/Kg at a stack power density of 700.2 W/Kg along with good stability (only 8.4% decay of initial capacitance after 5000 cycles at 4 A/g). The present work may provide a general approach for fabricating other metal oxide@carbon hybrid nanomaterials for various applications.

In this work, a core-shell hierarchical LiFe5O8@PPy nanocomposite has been successfully fabricated through a simple etching/regrowing method. The core buffer of highly conductive PPy nanotubes is introduced to enhance the electrochemical performance of LiFe5O8. Owing to improved electron transfer capability, charge transfer resistances of the core-shell nanostructured composites are decreased and the electrochemical properties are enhanced. The representative LiFe5O8@PPy nanocomposite exhibits a high specific capacitance of 292 F g−1 at a scan rate of 5 mV s−1, and an excellent cycling stability (82.99% after 10,000 cycles) because of the synergistic effect of LiFe5O8 nanosheets and PPy nanotubes. This study confirms that the as-prepared LiFe5O8@PPy nanocomposites are promising candidates for supercapacitor electrode materials.

Alternative anode materials are required to meet the urgent demand for high-power density lithium-ion batteries (LIBs) since commercial graphite anode is approaching its limits. Silicon with ultrahigh specific capacity and large abundance is proposed to be an attractive substitute as high-performance anode material. However, the practical application of Si-based materials in LIBs is still impeded by unsatisfied cycling ability. Herein, carbon-encapsulated nano-Si on graphite hybrid composite (nano-Si/G/C) is elaborately designed and fabricated through a facile and scalable process. In this structure, Si nanoparticles are adhering on bulk graphite and further encapsulating by asphalt derived carbon. Graphite can guarantee the conductivity and asphalt derived carbon can buffer the volume changes of nano-Si with controlled amount (below 30 wt%) as well as limit the side reactions between nano-Si and electrolyte. The obtained nano-Si/G/C anodes with different areal mass loadings ranging from 0.968 mg cm−2 to 4.28 mg cm−2 exhibit high cyclic stability. Furthermore, nano-Si/G/C anodes with multifarious reversible specific capacities (400–820 mA h g−1) could be synthesized by adjusting the production process. The superior properties indicate that the proposed nano-Si/G/C composites are of great potential toward the practical application in LIBs.

Poly(vinylidene fluoride) (PVDF) based polymer/ceramic nanocomposites for high energy density dielectrics have long been plagued by their low discharging efficiency (40–60%), which originates from the matrix with high bulk ferroelectric relaxation and the high-k ceramics with large conduction loss. In this work, a linear-like PVDF-based polymer dielectric is synthesized through grafting poly(methyl methacrylate) (PMMA) onto main chains of poly(vinyl fluoride-trifluoroethylene-chlorotrifluoroethylene) (P(VDF-TrFE-CTFE)) terpolymer via an atom transfer radical polymerization (ATRP) process. PMMA grafted terpolymer (P(VDF-TrFE-CTFE)-g-PMMA) shows linear-like dielectric characteristics accompanied with greatly enhanced discharging efficiency of ∼80% under 250 MV/m, which is over 100% higher than that of pristine terpolymer. To further improve its breakdown strength and discharging efficiency, the grafted terpolymer are then compounded with ultrasonic-exfoliated mica nanosheets (eMica) by solution-cast method. Thanks to the low hysteresis loss of linear-like dielectric matrix and the high insulating 2D mica nanosheets, the composite with the highest discharging efficiency of ∼78% under 250 MV/m is achieved. The maximum energy density of the optimized composite reaches 9.6 J/cm3, which is nearly 290% that of the pristine terpolymer. Besides, its discharging efficiency is about 74% under 450 MV/m, which is much more advantageous than the other PVDF-based polymer/ceramics composite dielectrics. This work suggests that utilizing polymer matrix with linear dielectric property and fillers with high insulating 2D structure might be a facile strategy to achieve composite dielectrics with simultaneously high energy density and high discharging efficiency.

In this research, by means of electrochemical cyclic voltammetries (CVs), the pathways of charge carrier interfacial transfer (IT) from TiO2 and Au/TiO2 rutile nanorod (NR) arrays to electrolyte were studied. For pure TiO2, the electron IT to O2 takes place via both the conduction band (CB) states and the surface states (SS). The UV light illumination increases the electron IT via CB states, but inhibits that via SS pathway. The CV results also evidenced that the Au nanoparticles (NPs) on TiO2 surface play dual roles of electron storage and electron IT pathway. Our results showed that the Au-induced defects, locating at Au/TiO2 perimeter, form an important additional pathway for electron IT to O2. UV light illumination increases the electron IT via Au NPs and Au-induced SS. In addition, we also revealed a special IT pathway of hot holes via the Au/TiO2 perimeter contributes to the full water oxidation under visible light illumination. Therefore, the Au/TiO2 perimeter region plays dual roles in the IT of both electrons and holes. Basing on these results, the IT pathways of charge carriers in Au/TiO2 were illustrated from the viewpoint of energy band diagram. The photocatalytic degradation of methyl orange, photoelectrochemical oxidation of water, and photogeneration of free hydroxyl radicals ( OH) were studied under UV and visible light illuminations. The association between the charge carrier IT pathways and the photocatalytic properties was also discussed.

The competitive water adsorption in the practical environment usually causes severe deactivation of the O3 decomposition catalysts. In this study, MnCO3 was used as precursor to prepare efficient and stable MnO2 catalyst for gaseous O3 decomposition in humid stream. The sample S-300, prepared by calcining MnCO3 at 300 °C for 6 h, exhibited 63% (80%) of removal efficiency for 120 (43) ppm of O3 under a high space velocity of 600 L g−1 h−1 and 50% (40%) of relative humidity at 25 °C, which is superior to the commercial O3 scrubber (oxide compound of Cu and Mn) and α-MnO2. However, even lower or higher treatment temperature did not further promote humid O3 decomposition. Thorough characterizations, especially by the temperature programmed and in situ DRIFTs experiments, demonstrate that the large amount of active oxygen vacancies and strong Lewis-acid sites together with the easy recovery of the occupied oxygen vacancies and weak interaction with water molecules accounted for the excellent O3 decomposition activity in humid stream. Besides, the developed pores by thermal decomposition of MnCO3 might also facilitate O3 removal. This study provides an easy and rational design of affordable and efficient catalysts for environmental application.

Developing new methods to use visible light is important for TiO2 photocatalysis. This research reported that the TiO2 rutile nanorod (NR) array shows high sub-band gap visible light response. By means of electrochemical cyclic voltammetries, the intrinsic occupied gap states of TiO2 NR array were identified. It was seen that the gap states can be switched from filled states to empty states by visible light illumination, which play the role of relay in promoting electrons from the valence band to the conduction band of TiO2 NRs after absorbing two visible photons. In a consequence, the TiO2 NR array shows the obvious anodic photocurrents for water photoelectrochemical oxidation and the photocatalytic degradation of methyl orange under visible light illumination. This study revealed the significance of the deep occupied gap states of TiO2 NR arrays, which are usually considered as recombination centers. Different from conventional photocatalysis arising from inter-band electron transition, the present research shows a different pathway to use visible light in TiO2 photocatalysis effectively, which should be highly meaningful for designing visibly-active TiO2 photocatalysts.

Paraquat (PQ) as a widely used herbicide has high toxicity. Therefore, it calls for development of sensitive analytic methods to monitor the residue of PQ in environment. In this work, a photoelectrochemical (PEC) sensing strategy via preparation of the photocathode of ITO/Au/Cu2O is proposed. The introduction of Au film in the PEC system significantly improves the photoelectric property of Cu2O, which may be attributed to the enhanced light utilization and the inhibited self-photoreduction of Cu2O. As expected, under the visible light illumination, the fabricated ITO/Au/Cu2O photocathode shows excellent sensitivity in determination of trace paraquat. The quantitative linear range is from 10-9 to 10-5 mol L-1 and the limit of detection (2.93×10-10 mol L-1) could be reached. For detection of real samples, the ITO/Au/Cu2O photocathode-based PEC sensor demonstrates interference-free, detection reproducibility and acceptable recoveries. This study highlights the heterostructure advantage of metal-semiconductor for promoting the PEC sensing application.

During the oxygen evolution reaction (OER), surface oxygen adsorption plays a crucial role in electrocatalysis. The stability of surface adsorption is closely related to the surface morphology of the catalyst. As one of the V-shaped nanotwins, 103 nano-twin grain boundary (103-TGB) has a special roof structure, which results in the presence of double dangling-O atoms at the junction of 103-TGB with (1 1 0) surface. In contrast to the ideal RuO2, the d-band center of Ru atoms located on the surface of 103-TGB is shifted to the Fermi level by 1.66 eV. Moreover, the key intermediates, namely *OH, *O, and *OOH, have suitable adsorption energies, providing a lower overpotential of OER ( I· OER ), via adsorbate evolving mechanism (AEM), of just 0.45 eV. Therefore, the OER via AEM is strongly focused on site 02 with double dangling-O atoms, revealing a synergistic effect due to the presence of both the 103-TGB defect and (1 1 0) surface.

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.

In this paper, L-cysteine (Cys) is firstly bonded to the surface of cotton non-woven (CO) fabric as esterification. In this way, Ag+ and tannic acid (TA) are adsorbed onto the modified fabric via complexation and hydrogen bond interaction. After a sustainable one-step redox reaction, a Cys modified CO fabric decorated with Ag NPs and TA (CO-Cys-Ag-TA) is prepared. Because of the stabilizing effect of Cys and TA, the synthesized Ag NPs with a mean size of 88.9 nm are uniformly distributed on the modified fabric surface. Through the comparative test, it has been revealed that the antibacterial activity of Ag NPs is improved after loading TA, and the loading of Ag NPs significantly reduces the cytotoxicity of TA. In this context, the bacteriostatic reduction rate of CO-Cys-Ag-TA against S. aureus and E. coli is close to 100%, and its antibacterial activities are greater than 98.5% after 50 washing cycles. Meanwhile, its cell viability value reaches up to 88.0% with the presence of 0.1 mg/mL to 0.8 mg/mL CO-Cys-Ag-TA.

In this study, novel magnetic infinite coordination polymer Fe3O4@Tb/AMP core-shell nanoparticles were rationally designed and fabricated as recyclable adsorbents for selective removal of anionic dyes from colored wastewater. The core-shell nanoparticles used in this study are composed of two components: the shell is the supramolecular infinite coordination polymers (ICPs) network formed by terbium ions (Tb3+) and adenosine 5′-monophosphate monohydrate (AMP) ligands and the core is the Fe3O4 nanoparticles which are encapsulated into the ICP network by the self-adaptive inclusion process. The prepared core-shell nanoparticles showed superiority in strong magnetism and selective adsorption towards anionic dyes, such as Alizarin Red (AR) and Congo Red (CR). Parameters that influenced the adsorption process, such as solution pH, salt concentration and adsorbent dosage were investigated. Under the optimal conditions, adsorption kinetics, isotherms and thermodynamics were also determined. Notably, this nano-adsorbent exhibited rapid adsorption feature (almost 96% dye removal in 5 min) and the adsorption isotherm data fitted quite well with the Langmuir model with an estimated maximum adsorption capacity of 357.14 mg g−1 for AR and 909.09 mg g−1 for CR at 298 K. This capacity could be further enhanced at the higher temperatures. In addition, the Fe3O4@Tb/AMP core-shell nanoparticles could be regenerated by a simple salt/ethanol-washing method and used with high recyclability over five cycles. With the magnetically separable Fe3O4@Tb/AMP core-shell nanoparticles as adsorbents, selective removal of toxic anionic dyes from colored wastewater could be realized directly, which is of great importance for the sustainable development of dye contaminated wastewater treatment technology.

A new method was developed in this paper to obtain self-film-forming polyaniline (PANI) grafting SiO2 (SiO2@PANI) sol which could form hydrophobic coatings on the surface of magnesium-lithium (Mg-Li) alloy directly for the purpose of anticorrosion. Firstly, covalently-jointed SiO2@PANI sol with core-shell structure was synthesized with (3-glycidoxypropyl)-trimethoxylsilane (GPTMS) modified SiO2 as core and PANI as shell, and then SiO2@PANI/VTMS sol was prepared after embedded SiO2@PANI with vinyl trimethoxysilane (VTMS). The structure and morphology of SiO2@PANI particle were characterized by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The hydrophobic and anticorrosion properties of SiO2@PANI/VTMS coating on Mg-Li alloy were evaluated by contact angle, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves. The results showed that aniline is polymerizing on the surface of SiO2 preferentially through the reaction between the epoxide group in GPTMS and amino group in aniline. The obtained SiO2@PANI sol dispersed stably in ethanol and supplied well microroughness to coatings, and subsequently enhanced hydrophobic properties of SiO2@PANI/VTMS coatings along with low surface energy supplied by VTMS. The hydrophobic angle of SiO2@PANI/VTMS coatings is high up to 133.8°. Consequently, the coatings have better corrosion resistance performance for the active Mg-Li alloy. Its impedance value is 5 × 104 Ω·cm2, and corrosion current density is merely 6.7 × 10−7 A·cm−2.

This paper reports an ultra-facile and energy-efficient microwave irradiation method for fabrication of phosphorus doped mesoporous carbon under ambient atmosphere. The fabricated phosphorus doped mesoporous carbons exhibit high specific surface area (up to 2055 m2 g−1), large pore volume (up to 2.73 cm3 g−1) and good conductivity, which specific capacitance reaches up to 210 F g−1, over 201 F g−1 of capacitance is retained even under a high current density of 20 A g−1, and the capacitance retention arrives 97.39% after 10,000 times charge/discharge cycles. Comparative study reveals that similar morphology is obtained by microwave irradiation and traditional pyrolytic carbonization, but more developed porosity and higher graphitization degree are achieved under microwave irradiation. The carbonization process completes in 1–3 min under microwave irradiation, which generally spends more than 2 h at a high temperature of over 600 °C by traditional pyrolytic method. No dramatic increase for surface oxygen content is found even it was fabricated under ambient atmosphere. The samples fabricated under microwave irradiation are potentially cost-efficient and high-performance electrode material for commercial supercapacitors.

MOFs attracted considerable attention as morphology templates and constitution precursors for synthesis of multiple functional nanocomposites due to their diverse and robust framework structure. In this work, a nickel-phosphide@carbon (Ni2P@C) composite with unique nanorod array morphology was synthesized via a facile phosphorization process using Ni(II)-zeolitic imidazolate framework-67 (ZIF-67-Ni) as the precursor. And the effect of phosphorization temperature on the morphology and structure of the products were carefully investigated. The products obtained under different phosphorization temperature were utilized as electrocatalysts for hydrogen evolution reaction (HER). The results showed that Ni2P@C nanorod array achieved under the phosphorization temperature of 400 °C demonstrated the highest electrocatalytic activity toward HER in 0.5 M sulfuric acid solution with a low overpotential of 186 mV at the current density of 10 mA cm−2. Also, high catalytic durability and chemical stability of the Ni2P@C nanorod array for HER were achieved. Combing the morphology and structure characterization experiments, the reason for high HER performance of Ni2P@C nanorod array obtained at the phosphorization temperature of 400 °C was discussed. This work provides a new guidance for the synthesis of high-performance MOFs-derived electrocatalyst for electrochemical HER.

The ternary-component NiCoAl-mixed metal oxides (NiCoAl-MMOs), which are expected to have a high capacitance, were successfully prepared as film electrode for capacitive deionization (CDI). Hexagonal NiCoAl-MMOs nanoplatelets with a lateral size between 250 and 400 nm densely covered the surface of the nickel foam substrate. With the optimal Ni/Co/Al ratio (1.5:1.5:1), NiCoAl-MMOs displayed a more well-distributed surface, better crystallinity, and higher specific surface area, while the Ni/Co/Al ratio of 1.5:1.5:1 was also optimal for the NiCoAl-MMOs film electrodes to achieve maximum capacitance of 1167 F/g. The NiCoAl-MMOs film electrodes possessed ideal pseudocapacitive behavior and good capacitive reversibility, and showed outstanding performance in CDI from the concomitant reconstruction of the layered double hydroxides by intercalating anions. The desalination capacity of the NiCoAl-MMOs film electrodes was 108.8 mg NaCl/g, which was significantly higher than that of binary-component NiAl-MMOs and carbon-based electrodes. The NiCoAl-MMOs electrodes were quickly regenerated by reversing the voltage, with a desorption rate of 81.36%. The electrosorption capacity was about 2.5 times higher than that of adsorption without bias, indicating that the intercalation of ions into NiCoAl-MMOs nanoplatelets was enhanced by applying an electric field. NiCoAl-MMOs showed great promise as a CDI electrode in desalination.

In this work a multifunctional micropore array (size from 5 to 42 μm) was produced by using one-step femtosecond laser microdrilling for oil-water and oil-oil separation. This novel method has many advantages, such as high precision (size error is less than 1 μm), simple operation (one step), extensible function (even complex microstructures) just to name a few. The prepared foil exhibited superhydrophilic and underwater superoleophobic properties, which can be used to separate the light oil (C8H18) and water mixtures. After heating in dark environment 0.5 h, the prepared foil showed superhydrophobic and underwater superoleophilic properties, and can be used to separate the heavy oil (C2H4Cl2) and water mixtures. In addition, the heated sample also showed robust ability to separate the immiscible organic liquid mixtures (formamide and C2H4Cl2), exhibiting multifunctional applications. Interestingly, the heated samples would recover its original superhydrophilicity after UV irradiation in ethanol for 1 h. The samples don’t contain any fluorinated compounds and display environmental stability even after sonic cleaning and scratch. This work will provide a new insight into the design of intelligent devices for oil/water mixtures separation, organic liquid mixtures separation, and water droplet manipulation.

Graphene directly grown on an 4H-SiC (0 0 0 1) substrate by chemical vapor deposition was studied: it was shown that Si evaporation process is not completely halted during graphene growth when TG ≥ 1400 °C, the SiC substrate decomposes at the position of graphene coverage. AFM and Raman spectrum results reveal that carbon concentration significantly influences graphene growth rate and morphology/structure. It is found that the quality of graphene film depends on the growth temperature and the flow of carbon source. We develop a new gradient growth method to produce a feasible graphene material for electronic devices. Graphene grown by this method has a flat-morphology structure, low wrinkle density, high crystal quality, good uniformity, and outstanding electrical transport properties. Nitrogen doping has an n-type doping effect on graphene carrier concentration. The main component of nitrogen-bond type is the graphitic configuration. The graphene material with nitrogen doping reaches a record mobility of 9010 cm2/V·s by room temperature Hall effect measurement, indicating graphene grown by gradient method with suitable nitrogen doping could yield a high quality film comparable to that by traditional method.