Nickel based materials have been intensively investigated and considered as good potential electrode materials for pseudocapacitors due to their high theoretical specific capacity values, high ...chemical and thermal stability, ready availability, environmentally benign nature and lower cost. This review firstly examines recent progress in nickel oxides or nickel hydroxides for high performance pseudocapacitor electrodes. The advances of hybrid electrodes are then assessed to include hybrid systems of nickel based materials with compounds such as carbonaceous materials, metal and transition metal oxides or hydroxides, in which various strategies have been adopted to improve the electrical conductivity of nickel oxides or hydroxides. Furthermore, the energy density and power density of some recently reported NiO, nickel based composites and NiCo2O4 are summarized and discussed. Finally, we provide some perspectives as to the future directions of this intriguing field.
•Nickel based materials for high performance pseudocapacitor electrodes were reviewed.•Strategies adopted to improve the electrical conductivity of nickel based materials were assessed in details.•The energy density and power density of some recent nickel based materials were summarized and discussed.•Perspectives as to the future directions of nickel based materials were provided.
Multi-walled carbon nanotubes (MWNTs) were modified with poly(hexamethylene adipamide) (also known as Nylon 66) via a controlled polymer solution crystallization method. A “nanohybrid shish kebab” ...(NHSK) structure was found wherein the MWNT resembled the shish while Nylon 66 lamellar crystals formed the kebabs. These Nylon 66-functionalized MWNTs were used as precursors to prepare polymer/MWNT nanocomposites. Excellent dispersion was revealed by optical and electron microscopies. Nitric acid etching of the nanocomposites showed that MWNT formed a robust network in Nylon 66. Non-isothermal DSC results showed multiple melting peaks, which can be attributed to lamellar thickness changes upon heating. The crystallite sizes
L
100 and
L
010 of Nylon 66, determined by WAXD, decreased with increasing MWNT contents. Isothermal DSC results showed that crystallization kinetics increased first and then decreased with increasing MWNT contents in Nylon 66. This study showed that the effect of MWNTs on Nylon 66 crystallization is twofold: MWNTs provide heterogeneous nucleation sites for Nylon 66 crystallization while the tube network structure hinders large crystal growth.
•Novel attapulgite(ATP)-CeO2/MoS2 ternary nanocomposites were fabricated.•ATP possessed outstanding adsorption property and enhanced the stability of the network structure.•CeO2/MoS2 couples ...facilitated the separation of photo-induced electrons and holes.•Mass ratio of CeO2/MoS2 influenced the photocatalytic oxidation desulfurization.
Novel attapulgite(ATP)-CeO2/MoS2 ternary nanocomposites were synthesized by microwave assisted assembly method. The structures of the nanocomposites were characterized by XRD, FT-IR, UV–vis, XPS and in situ TEM. The photocatalytic activities of ATP-CeO2/MoS2 composites were investigated by degradating dibenzothiophene (DBT) in gasoline under visible light irradiation. The effect of the mass ratio of CeO2 to MoS2 on photocatalytic activity was investigated. The results indicate that the three-dimensional network structure is firmly constructed by ATP skeleton, CeO2 particles and MoS2 nanosheet which effectively increase the surface area of the composites and promote the separation of electrons and holes by resulting electronic transmission channels of multi-channel in space. The degradation rate of DBT can reach 95% under 3h irradiation when the mass ratio of CeO2/MoS2 is 4/10. A plausible mechanism for the photocatalytic oxidative desulfurization of this nanocomposite is put forward.
In this study, nanosilica particles were prepared from self-made silica gel under the protection of citric acid in situ complexation and ethyl acetate as the latent acid reagent. The effects of ethyl ...acetate, citric acid, reaction temperature, and reaction time on the particle size of nanosilica were studied. The optimum process parameters were determined as follows: V
ethyl acetate
: V
silica sol
= 9:50, citric acid addition amount 3.64%, reaction time 8 h, and reaction temperature 70 °C. The products were characterized by IR, XRD, SEM and TEM analyses. The results show that the nano-silica particles prepared by complexation precipitation method employing silica sol as silicon source has good dispersion with average particle size controlled about 19.44 nm. The method has numerous advantages over the conventional inverse extraction method under colloid protection, and is expected to achieve industrial production.
Spin-orbit interaction-driven phenomena such as the spin Hall and Rashba effect in ferromagnetic/heavy metal bilayers enables efficient manipulation of the magnetization via electric current. ...However, the underlying mechanism for the spin-orbit interaction-driven phenomena remains unsettled. Here we develop a sensitive spin-orbit torque magnetometer based on the magneto-optic Kerr effect that measures the spin-orbit torque vectors for cobalt iron boron/platinum bilayers over a wide thickness range. We observe that the Slonczewski-like torque inversely scales with the ferromagnet thickness, and the field-like torque has a threshold effect that appears only when the ferromagnetic layer is thinner than 1 nm. Through a thickness-dependence study with an additional copper insertion layer at the interface, we conclude that the dominant mechanism for the spin-orbit interaction-driven phenomena in this system is the spin Hall effect. However, there is also a distinct interface contribution, which may be because of the Rashba effect.
We report herein a unique means to periodically pattern polymeric materials on individual carbon nanotubes (CNTs) using a controlled polymer crystallization method. One-dimensional (1D) CNTs were ...periodically decorated with polymer lamellar crystals, resulting in nano-hybrid shish-kebab (NHSK) structures. The periodicity of the polymer lamellae varies from 20 to 150 nm. The kebabs are approximately 5−10 nm thick (along CNT direction) with a lateral size of ∼20 nm to micrometers, which can be readily controlled by varying crystallization conditions. Both polyethylene and Nylon 66 were successfully decorated on single-walled carbon nanotubes (SWNTs), multiwalled carbon nanotubes (MWNTs), as well as vapor grown carbon nanofibers (CNFs). The formation mechanism was attributed to “size-dependent soft epitaxy”. Because NHSK formation conditions depend on CNT structures, it further provides a unique opportunity for CNT separation. The reported method opens a gateway to periodically patterning polymers and different functional groups on individual CNTs in an ordered and controlled manner, an attractive research field that is yet to be explored.
A novel Bi2W1−xMoxO6/Montmorillonite (MMT) nanocomposite was prepared by one-pot hydrothermal method. XRD, TEM, Raman, UV–vis, FT-IR, PL and XPS were employed to characterize the nanocomposites. The ...photocatalytic desulfurization properties of Bi2W1−xMoxO6/MMT nanocomposites were performed by oxidizing dibenzothiophene (DBT) in the model oil under visible light irradiation. Results indicate that the molar fraction of Mo doping has critical impact on the desulfurization rate. Adequate Mo doping may form well-defined “solid solution/co-precipitation” heterostructure of Bi2W1−xMoxO6/Bi2MoO6, which enhances the visible light absorption efficiency and promotes the separation rate of photogenerated electron-hole pairs, thus leads to the improved photocatalytic desulfurization performance. The desulfurization rate of the model oil can reach 95% when the molar fraction x is 0.7 under visible light irradiation for 3 h.
•Novel Bi2W1−xMoxO6/montmorillonite nanocomposites were fabricated.•Montmorillonite benefited the adsorption of dibenzothiophene and immobilization of Bi2W1−xMoxO6 nanosheet.•Coherent Bi2W1−xMoxO6/Bi2MoO6 heterostructure facilitated the separation of photogenerated electron-hole pairs.•Molar fraction of Mo influenced the photocatalytic oxidation desulfurization.
Hybrid inorganic-organic perovskites have quickly evolved as a promising group of materials for solar cells and optoelectronic applications mainly owing to the inexpensive materials, relatively ...simple and versatile fabrication and high power conversion efficiency (PCE). The certified energy conversion efficiency for perovskite solar cell (PSC) has reached above 20%, which is compatible to the current best for commercial applications. However, long-term stabilities of the materials and devices remain to be the biggest challenging issue for realistic implementation of the PSCs. This article discusses the key issues related to the stability of perovskite absorbing layer including crystal structural stability, chemical stability under moisture, oxygen, illumination and interface reaction, effects of electron-transporting materials (ETM), hole-transporting materials (HTM), contact electrodes, ion migration and preparation conditions. Towards the end, prospective strategies for improving the stability of PSCs are also briefly discussed and summarized. We focus on recent understanding of the stability of materials and devices and our perspectives about the strategies for the stability improvement.
Display omitted
•Progress in stabilizing hybrid perovskite solar cells (PSCs) is reviewed.•Key issues related to the stability of perovskite components are evaluated.•Optimizing multiple factors associated with component structures is essential.•Strategies for improving the stability of PSCs are discussed and summarized.
Schizophrenia is a complex genetic disorder, the non-Mendelian features of which are likely complicated by epigenetic factors yet to be elucidated. Here, we performed RNA sequencing of peripheral ...blood RNA from monozygotic twins discordant for schizophrenia, and identified a schizophrenia-associated upregulated long noncoding RNA (lncRNA, AC006129.1) that participates in the inflammatory response by enhancing SOCS3 and CASP1 expression in schizophrenia patients and further validated this finding in AC006129.1-overexpressing mice showing schizophrenia-related abnormal behaviors. We find that AC006129.1 binds to the promoter region of the transcriptional repressor Capicua (CIC), facilitates the interactions of DNA methyltransferases with the CIC promoter, and promotes DNA methylation-mediated CIC downregulation, thereby ameliorating CIC-induced SOCS3 and CASP1 repression. Derepression of SOCS3 enhances the anti-inflammatory response by inhibiting JAK/STAT-signaling activation. Our findings reveal an epigenetic mechanism with etiological and therapeutic implications for schizophrenia.
We report the design of two collagen-mimetic peptide sequences, NSI and NSII, that self-assemble into structurally defined nanoscale sheets. The underlying structure of these nanosheets can be ...understood in terms of the layered packing of collagen triple helices in two dimensions. These nanosheet assemblies represent a novel morphology for collagen-based materials, which, on the basis of their defined structure, may be envisioned as potentially biocompatible platforms for controlled presentation of chemical functionality at the nanoscale. The molecularly programmed self-assembly of peptides NSI and NSII into nanosheets suggests that sequence-specific macromolecules offer significant promise as design elements for two-dimensional (2D) assemblies. This investigation provides a design rubric for fabrication of structurally defined, peptide-based nanosheets using the principles of solution-based self-assembly facilitated through complementary electrostatic interactions.