Controlled Growth of 3D Interpenetrated Networks by NiCo2O4 and Graphdiyne for High-Performance Supercapacitor.

In this paper, the 2D all-carbon graphdiyne, which possesses superior 2D strength and high mixed conductivities for both electrons and ions, is used to protect nickel cobalt oxide nanostructures with multidimensions. The in situ grown graphdiyne seamlessly wraps on nanostructures to form 3D interpenetrating networks, leading to significant improvement in the conductivity and avoidance of the structural degradation. The assembled hybrid asymmetric supercapacitor showed a high specific capacitance of 200.9 F g-1 at 1 A g-1 with an energy density of 62.8 Wh kg-1 and a power density of 747.9 W kg-1. The device also showed a preeminent rate capability (86.4% capacitance retention, while the current density was increased from 1 to 20 A g-1) and an ultrastable long-term cycling performance (the capacitance retention is about 97.7% after 10 000 cycles at a high current density of 20 A g-1).

Facile synthesis of Bi2MoO6/reduced graphene oxide composites as anode materials towards enhanced lithium storage performance.

Bi2MoO6/reduced graphene oxide (Bi2MoO6/rGO) composites were fabricated by a facile one-pot hydrothermal approach, in which Bi2MoO6 nanosheets and rGO were simultaneously obtained. The structure and composition of the as-synthesized Bi2MoO6 and Bi2MoO6/rGO materials were characterized via FT-IR, BET, TGA, XRD, TEM, SEM and XPS analyses, and the electrochemical performance of Bi2MoO6/rGO as an anode in a lithium-ion battery was investigated. Compared with pristine Bi2MoO6, the Bi2MoO6/rGO composites have higher capacities, better cycle stability and higher rates. For a current density of 100 mA g-1, the initial discharge capacities of the Bi2MoO6/rGO-20 and pristine Bi2MoO6 were 1049.6 mAh g-1 and 528.5 mAh g-1, respectively. After 100 cycles, the capacity retention for the Bi2MoO6/rGO-20 and pristine Bi2MoO6 were respectively 80.4% and 30.7% using the 2nd cycle capacities (895.8 and 402.4 mAh g-1) as references. The enhanced electrochemical performance can be ascribed to the synergistic effect of the Bi2MoO6 and rGO sheets, which dramatically improves the conductivities of the Bi2MoO6/rGO anodes. In addition, the rGO sheets also supply electron transfer routes for the anode and suppress volume changes of Bi2MoO6 nanosheets during the charge-discharge cycles.

Facile synthesis of graphitic C3N4 nanoporous-tube with high enhancement of visible-light photocatalytic activity.

A simple and convenient method was used to synthesize a graphitic carbon nitride (g-C3N4) nanoporous-tube by using SiO2 nanoparticles as pore formers. The structure of the g-C3N4 nanoporous-tube was characterized by the SEM and TEM images. Taking photodegradation of RhB as an example, the photocatalytic activity of the as-prepared g-C3N4 nanoporous-tube was investigated. It can photodegrade 90% RhB in 40 min under visible-light irradiation and obtain a k value of 0.04491 min-1, which is 8.16 times that of bulk g-C3N4, 3.09 times that of tubular g-C3N4 and 1.48 times that of tubular g-C3N4-SiO2. The significant enhancement in photocatalytic efficiency is due to the edge effect of the pores and the special structure of the tubes. In addition, the possible mechanism of photocatalytic degradation of RhB was also proposed based on the trapping experiment of active species, which indicated that the superoxide radicals ([Formula: see text]) and the holes (h +) were the main reactive species in this photocatalyst. This work may open up a new idea of innovation in g-C3N4 structure and inspire its follow-up study.

Enhanced visible light photocatalytic hydrogen evolution over porphyrin hybridized graphitic carbon nitride.

Tetra (4-carboxyphenyl) porphyrin (TCPP) was loaded on the surface of Pt/g-C3N4 via a simple adsorption process, and the microstructure and chemical structure of the composites were characterized by high resolution transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, UV-visible diffused reflectance spectroscopy and photoluminescence spectroscopy. Loading TCPP onto Pt/g-C3N4 enhanced the visible-light-driven photocatalytic evolution of H2 from water. The TCPP/Pt/g-C3N4 composite with a TCPP loading of 1wt% had the highest photoactivity, which was 2.1 times higher than that of Pt/g-C3N4. This improvement is attributed to enhanced visible light utilization by the TCPP/Pt/g-C3N4 resulting from the strong visible light response of TCPP. In addition, the formed organic heterostructure between TCPP and g-C3N4 with overlapping bad gaps accelerates the electron transfer and inhibits the recombination of the photogenerated electrons and holes on g-C3N4.