Hydrothermally synthesized ternary heterostructured MoS2/Al2O3/g-C3N4 photocatalyst

A multifaceted ternary MoS2/Al2O3/g-C3N4 nanocomposite was prepared from a simple and facile hydrothermal method, which has good photocatalytic performance for the degradation of crystal violet (CV) dye under visible light irradiation. As a result of wide structural features for the charge separation mechanism, the formation of a ternary heterojunction affects the photocatalytic activity of the MoS2/Al2O3/g-C3N4 nanocomposite remarkably. The photocatalytic activity of ternary nanocomposite was approximately 10.28 and 1.65 times higher than that of pure g-C3N4 and 20Al-gCN, respectively. More significantly, the ternary nanocomposite also showed good photostability and reusability. The enhanced visible light photocatalytic activity was attributed to the effective photocatalytic mechanism of charge separation of the ternary system, whereas the surface properties were key factors for photodegradation of the CV dye

Carbon/CuO nanosphere-anchored g-C3N4 nanosheets as ternary electrode material for supercapacitors

Novel electrode materials for supercapacitors comprised of carbon and copper oxide (CuO) nanospheres on graphitic carbon nitride (g-C3N4) nanosheets, denoted as C/CuO@g-C3N4 are self-assembled via a one-step co-pyrolysis decomposition method. The pure g-C3N4 and C/CuO@g-C3N4 were confirmed by powder X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), thermal gravimetric and differential thermal analysis (TG-DTA), X-ray photoelectron spectroscopy (XPS), N-2 adsorption/desorption studies and Fourier-transform infrared spectroscopy (FTIR). The specific capacitance was 247.2 F g(-1) in 0.5 M NaOH at a current density of 1 Ag-1, and more than 92.1% of the capacitance was retained after 6000 cycles. The property enhancement was ascribed to the synergistic effects of the three components in the composite. These results suggest that C/CuO@g-C3N4 possessed an excellent cyclic stability with respect to their capacity performance as electrode materials

Single-step hydrothermal synthesis of wrinkled graphene wrapped TiO2 nanotubes for photocatalytic hydrogen production and supercapacitor applications

Herein, we discuss the synthesis of reduced graphene oxide and TiO2 (rGO-TiO2) nanocomposites with varying ratios of rGO to TiO2 by hydrothermal method. Photocatalytic ability of the nanocomposites was assessed for H2 production under natural sunlight. At 5 wt% GO loading, the rGO-TiO2 exhibited 24,880 ??mol/g/h H2, 12.9 times to commercial P25-TiO2 (1920 ??mol/g/h). The symmetric supercapacitor device fabricated using rGO-TiO2 demonstrated 160 F/g specific capacitance with 99% retention. The efficient charge carrier separation and transportation between TiO2 nanotubes and rGO resulted high photocatalytic activity. The synergistic double layer pseudo capacitor behavior of rGO-TiO2 is the reason for improved specific capacitance

Physicochemcial characteristic of CdS-anchored porous WS2 hybrid in the photocatalytic degradation of crystal violet under UV and visible light irradiation

In this work, we report the synthesis of CdS-incorporated porous WS2 by a simple hydrothermal method. The structural, morphological, and optical properties of the samples were examined by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), high resolution X-ray photoelectron spectroscopy (XPS) and UV-visible spectrometry. The photocatalytic activities were established for degradation of crystal violet (CV) under UV and visible light irradiation. The CdS-incorporated porous WS2 hybrid demonstrated high photocatalytic activity for degradation of CV pollutant compared to pure CdS nanoparticles and porous WS2 sheets. This result implies that the CdS-incorporated porous WS2 promoted more electron-hole pair transformation under UV and visible light irradiation. This significant enhancement of photocatalytic efficiency of CdS-incorporated porous WS2 photocatalyst under visible light can be ascribed to the presence of CdS nanospheres on the meshed-like WS2 sheets which potentially improves absorption in the visible range enabled by surface plasmon resonance effect of CdS nanospheres. The photostability and reusability of the CdS-porous WS2 were examined through recycling experiments.ope

In situ fabrication of the Bi2O3-V2O5 hybrid embedded with graphitic carbon nitride nanosheets: Oxygen vacancies mediated enhanced visible-light-driven photocatalytic degradation of organic pollutants and hydrogen evolution

Novel mesoporous ternary hybrids comprising Bi2O3/V2O5 photocatalysts anchored on graphitic carbon nitride (g-C3N4) nanosheets were synthesized via an in situ co-pyrolysis approach and characterized by a series of techniques, including X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller analysis, thermogravimetric-differential thermal analysis, Fourier transform infrared spectroscopy, ultraviolet-visible spectrometry, photoluminescence and electron paramagnetic resonance (EPR). The hybrids were subsequently tested as photocatalysts for the degradation of the phenol red (PR) pollutant under visible light irradiation. The well-designed ternary hybrids showed pure and randomly distributed Bi2O3/V2O5 (denoted as BiV) nanoparticles on monodispersed g-C3N4 nanosheets. The asprepared ternary Bi2O3/V2O5@ g-C3N4 (i.e., BiV@g-C3N4) hybrids demonstrated high specific surface areas with remarkable mesoporous characteristics. The photodegradation efficiencies of the ternary hybrids for PR were 1.2 and 1.8 times higher than those of binary BiV and pristine Bi2O3, respectively, at 50 min irradiation time under simulated solar light irradiation. At the end of the phototreatment, the amount of PR pollutant was reduced to 98.1% in 50 min by using the BiV@g-C3N4 nanocomposites under simulated solar light irradiation and more efficient for photocatalytic H-2 production. Based on an electrochemical analysis, we propose a photocatalytic degradation pathway for PR under visible light irradiation. In addition, the BiV@g-C3N4 nanocomposite photocatalysts exhibited both long-term stability and photocatalytic efficiency for the degradation of the PR dye. The excellent photoelectrochemical performance of the BiV@g-C3N4 photocatalysts can be ascribed to their highly dispersed V2O5 and Bi2O3 nanoparticles, mesoporous structure, and high specific surface area (83.75 m(2) g(-1))

1D Bi2S3 nanorod/2D e-WS2 nanosheet heterojunction photocatalyst for enhanced photocatalytic activity

The development of high-activity, long-life, precious-metal-free photocatalysts for redox reactions in photoelectrochemical cells and fuel cells remains challenging. The synthesis of high-activity heterostructured photocatalysts is crucial for efficient energy conversion strategies. Herein, a novel photocatalyst based on 1D Bi2S3 nanorods self-assembled on 2D exfoliated tungsten disulfide (e-WS2) nanosheets has been developed for the degradation of methyl orange (MO) dye in aqueous solution. We demonstrate a novel and facile hydrothermal method for the synthesis of a Bi2S3 nanorod/e-WS2 nanosheet heterostructure. The photocatalytic properties of the heterostructure under visible light were investigated. Enhanced photocatalytic activity was attributed to the presence of strong surface active sites, as well as the specific morphology of the composite. We also observed the fast transfer of electron-hole pairs at the material interface. This work demonstrates a non-noble semiconductor photocatalyst for the degradation of pollutants and evolution of H2

Effects of thermal contact resistance on the thermal conductivity of core-shell nanoparticle polymer composites

This paper describes a numerical study on the thermal conductivity (TC) of core-shell nanoparticle polymer composites under the effects of thermal contact resistance (TCR), in addition to other parameters. Finite element method is used for both numerical simulation and solving the related nonlinear equations. Consequently, the effective thermal conductivity (ETC) depends significantly on the TCR, and it decreases sharply for larger volume fractions (VF) and larger TC of core-shell. The ETC from the present study matches well with that obtained by Felske model only if the TCR is negligible. Core VF of 0.516 times greater than that of shell is a necessary condition for an existence of the maximum ETC regardless of the presence of the TCR. In addition, the ETC is independent on the TCR at core-shell interface when either the TCR at shell-matrix interface is large or the TC of shell approaches a critical value. Many other good guidance are provided for enhancing the TC of core-shell nanoparticle polymer composites, and it plays an important role in producing advanced polymer composites.ope

Hydrothermally synthesized highly dispersed Na2Ti3O7 nanotubes and their photocatalytic degradation and H-2 evolution activity under UV and simulated solar light irradiation

Photocatalytic water splitting technologies are currently being considered for alternative energy sources. However, the strong demand for a high H-2 production rate will present conflicting requirements of excellent photoactivity and low-cost photocatalysts. The first alternative may be abundant nanostructured titanate-related materials as a photocatalyst. Here, we report highly dispersed Na2Ti3O7 nanotubes synthesized via a facile hydrothermal route for photocatalytic degradation of Rhodamine B (RhB) and the water splitting under UV-visible light irradiation. Compared with commercial TiO2, the nanostructured Na2Ti3O7 demonstrated excellent photodegradation and water splitting performance, thus addressing the need for low-cost photocatalysts. The as-synthesized Na2Ti3O7 nanotubes exhibited desirable photodegradation, and rate of H-2 production was 1,755 mu mol center dot g(-1)center dot h(-1) and 1,130 mu mol center dot g(-1)center dot h(-1) under UV and simulated solar light irradiation, respectively; the resulting as-synthesized Na2Ti3O7 nanotubes are active in UV light than that of visible light response