Search

Owing to the metalloid characteristic and superior electrical conductivity, the metal phosphides have received increasing interests in energy storage systems. Here, x rGO/Ni 2 P composites are successfully synthesized via an In-situ phosphorization process with GO/Ni-MOF as precursors. Compared to pure Ni 2 P, the x rGO/Ni 2 P composites appear enhanced electrochemical properties in terms of the specific capacitance and cycling performance as electrodes for supercapacitors. Especially, the 2rGO/Ni 2 P electrode shows a highest specific capacitance of 890 F g −1 at 1 A g −1 among the obtained composites. The enhancement can be attributed to the inherited structure from Ni-MOF and the well assembled of rGO and Ni 2 P through the In-situ conversion process. Moreover, when applied as positive electrode in a hybrid supercapacitor, an energy density of 35.9 W h kg −1 at a power density of 752 W kg −1 has been achieved. This work provides an In-situ conversion strategy for the synthesis of rGO/Ni 2 P composite which might be a promising electrode material for SCs. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel hierarchical CdS-DETA@CoP composite is first synthesized. • CdS-DETA@CoP exhibits excellent visible-light-driven photocatalytic performance. • The synergistic effect can boost the separation efficiency of electron-hole pairs. The photolysis of water using photocatalysts under sunlight irradiation for hydrogen generation reaction is an efficient strategy to solve energy and environmental issues. Herein, a novel hierarchical CdS-DETA@CoP composite was fabricated and applied to visible-light-driven photocatalytic water splitting for generating H 2. To achieve this goal, we first prepared a 3D hierarchical CoP co-catalyst via direct phosphatization of the ZIF-67 precursor. Then, two-dimensional (2D) CdS-DETA nanosheets were in situ grown on the surface of hierarchical CoP through a facile water bath method, obtaining a CdS-DETA@CoP composite with a high surface area. The CdS-DETA@CoP composite with 20 wt% CoP exhibits a maximum photocatalytic H 2 evolution rate of 48.76 mmol g–1h−1 under visible light irradiation with lactic acid as the sacrificial reagent, which is 46.4 times as high as CdS-DETA. The synergistic effect between CdS-DETA and CoP induced remarkable ability of light-harvesting and efficient separation of photogenerated electron-hole pairs, thus profoundly promoting the activity and stability. The excellent activity is also closely related to the better dispersion of CdS-DETA on the surface of hierarchical CoP co-catalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sn/SnP 2 O 7 composite was synthesized by anodization and phosphorization. • The material was comprised of Sn nanoparticles embedded in the SnP 2 O 7 matrix. • Sn/SnP 2 O 7 exhibits excellent storage for Li and Na ions compared to Sn/SnO x. • Reversible capacities with a 100 % efficiency were achieved up to 1000 cycles. Two types of Sn-based nanostructured materials have been investigated as anodes in lithium-ion batteries (LIB) and sodium-ion batteries (SIB). Firstly, nanostructured Sn/SnO x powders were synthesized by one-step anodic oxidation of Sn foil in an alkaline electrolyte followed by mechanical separation of the anodic film from the remaining substrate. Secondly, as-anodized powders were converted for the first time to tin oxyphosphate (Sn/SnP 2 O 7) hybrid via a simple phosphorization with red phosphorous at 500 °C. The XRD and HR-TEM analyses confirmed that the hybrid was comprised of Sn nanoparticles embedded in the SnP 2 O 7 matrix. When used as anode materials, the Sn/SnP 2 O 7 exhibits excellent storage performance for lithium and sodium ions compared to Sn/SnO x that can be attributed to the metal/matrix structure which is not only conducive to the electron transport but also can facilitate the accommodation of volume changes during intercalation/deintercalation processes. A stable reversible capacity with an excellent coulombic efficiency of nearly 100% at different current densities even up to 1000 cycles was achieved for the Sn/SnP 2 O 7 anode in LIB. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel concept of hierarchical-dimensional material strategy for efficient lithium storage. • High-rate Li-ion battery application and the relationship between structural hierarchy and performances. • Facile methodology for the construction of hierarchical-dimensional materials. The pulverization and aggregation of metal-based anode materials caused by considerable volume expansion during repeated lithiation/de-lithiation lead to poor lithium storage performance for lithium-ion batteries (LIBs). Herein, intricate-cavity hollow cobalt phosphide (S-CoP), which is fabricated by the weave of one-dimension (1D) hollow nanorods and further self-assemble of the weaved two-dimension (2D) substructures, is exploited as anode material to accommodate high-performance lithium storage. The self-assembled hierarchical-dimensional architecture, together with the intricate void structure of the nanorods, construct highly accessible surfaces which facilitate electrolyte wetting, diffusion distance decreasing, and thus rapid kinetics during lithium storage. Meanwhile, the developed pore volumes gifts flexible space to alleviate the huge volume change, delivering longer service life for LIBs. As a result, the LIBs based on the designed CoP afford a favorable rate behavior and stable reversible cycling performance. This work provides fresh insights in the design and construction of advanced anode materials for LIBs, which is hopeful to be also enlightening for other high-performance energy systems. [ABSTRACT FROM AUTHOR]

• Develop new self-assembled Ni/Co phosphides composite spheres. • Carbon nanospheres via a hydrothermal process and effective manner. • Exhibit excellent HER electrocatalytic activity. • Significant potentials in composite electrocatalyst design. Because of their high catalytic activity and abundant resources, nonprecious transition metal phosphides are favorable substitutes for noble metals as hydrogen evolution reaction (HER) electrocatalysts. In this work, self-assembled Ni/Co phosphide composite N-doped carbon spheres were successfully prepared via a hydrothermal process, which had abundant exposed active sites for the HER. The as-obtained samples exhibited excellent electrocatalytic activity for the HER with an overpotential of only 160 mV (vs. RHE) at a current density of 10 mA cm−2 in a 0.5 M H 2 SO 4 solution and a comparatively low Tafel slope (57 mV dec−1). Additionally, the Ni 2 P/CoP spheres also show good stability after 120 h and 5000 cycles of a cyclic voltammetry test. Their highly efficient catalytic activity for the HER is attributed to the specific spherical structure, which provides exposed Ni 2 P and CoP for favorable adsorption and desorption of hydrogen. Therefore, nonprecious transition metal phosphide spheres may provide a promising strategy to improve the catalytic activity of HER electrocatalysts. [ABSTRACT FROM AUTHOR]