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The MOFs materials exist potential application prospects in the energy storage field for their high specific surface area and porosity. However, the MOFs materials also suffer from poor conductivity during the charging and discharging processes. Compared with MOFs, MOFs-derived metal oxides not only inherit the porosity of the MOFs, but also present high conductivity owing to the derived carbon. Herein, an effective approach for encapsulating CoFe2O4 into the derived carbon, which not only increases their conductivity but also restrains the volume expansion, and had excellent reaction kinetics. In this work, CoFe2O4 nanoparticles have been synthesized by one-step annealed process. The electrode is used as the anode for LIBs and found to have long-term stability of 491 mAh g−1 at a current density of 1.0 A g−1 even after 500 cycles. The CoFe2O4 electrode exhibits appreciable electrochemical performance, including 783 and 482 mAh g−1 at the current densities of 0.1 and 2.0 A g−1, respectively. Such excellent electrochemical properties are ascribed to the porous structure of MOFs, which effectively promotes ion/charge transmission. This will guide material design and optimization of battery communities and electrochemical energy storage applications. [ABSTRACT FROM AUTHOR]

A new averaged general dynamic equation (GDE) for nanoparticles in the turbulent flow is derived by considering the combined effect of convection, Brownian diffusion, turbulent diffusion, turbulent coagulation, and fluctuating coagulation. The equation is solved with the Taylor-series expansion moment method in a turbulent pipe flow. The experiments are performed. The numerical results of particle size distribution correlate well with the experimental data. The results show that, for a turbulent nanoparticulate flow, a fluctuating coagulation term should be included in the averaged particle GDE. The larger the Schmidt number is and the lower the Reynolds number is, the smaller the value of ratio of particle diameter at the outlet to that at the inlet is. At the outlet, the particle number concentration increases from the near-wall region to the near-center region. The larger the Schmidt number is and the higher the Reynolds number is, the larger the difference in particle number concentration between the near-wall region and near-center region is. Particle polydispersity increases from the near-center region to the near-wall region. The particles with a smaller Schmidt number and the flow with a higher Reynolds number show a higher polydispersity. The degree of particle polydispersity is higher considering fluctuating coagulation than that without considering fluctuating coagulation. [ABSTRACT FROM AUTHOR]

Aerosol control is a big revolution in production and use of submicronic particles. Developing a novel aerosol control technology in the area is the study objective of this paper. Attributing to the aerosol control potential in acoustics, a normal 16-sided aerosol aggregation chamber (pelletier dish) symmetrically installed with 16 poles of Helmholtz sound source (HSS) is successfully used to aggregate smog aerosols. The aerosols are generated by the combustion of chemical material. In the acoustic conditions of 2, 4, 8 and 16 beams of opposing waves, the shapes of aerosol distribution always display as the specific aerosol petals of number equaling to the operating number of HSS. With the increase of the operating number, the removal effectiveness rises gradually to 1.5 wavelengths, obviously larger than half wavelengths achieved in the previous study. The results are repeatability in experiment, and especially the aerosol aggregation can be pre-designed by acoustic field simulation. Unlabelled Image • Aerosol aggregation in 16-side waveguide coupled with multi-pole sources is studied. • A new tuning control method on the number of aerosol aggregation petals is focused. • The removal effectiveness increases with the increase of aerosol petal number. • The patterns of aerosol distribution and simulated acoustic field are similar. • PM 2.5 removal efficiency in 2 poles of Helmholtz sound sources achieves about 82%. [ABSTRACT FROM AUTHOR]

Generally, one-dimensional nanowires (NWs) show higher electron mobility than their nanoparticles, due to that they can provide a direct transport channel for photogenerated carriers of the assembled devices. In this work, gallium nitride (GaN) NWs prepared by electrospinning technique were applied into as a substitute for GaN particles (GaN-P) in GaN-based photoelectrochemical (PEC) self-powered ultraviolet (UV) photodetectors. Results show the UV photodetectors based on GaN-NWs can exhibit a rapid response ( t r  = 0.28 s, t d  = 0.25 s), which is highly improved compared to that of the GaN-P based device ( t r  = 0.37 s, t d  = 0.3 s). Moreover, the GaN-NW UV photodetectors also perform high reproducibility and stability (testing for 80 days). This research indicates that the GaN-NW-based photoanodes will further widen the advancements for PEC-type self-powered UV photodetectors. [ABSTRACT FROM AUTHOR]

Transition metal sulfides coupled with carbon materials hold a promising application platform for high-performance supercapacitors. Herein, we report a strategy to fabricate a type of integrated CoS x hollow nanoparticles (HNPs)/C hybrid nanofibers via electrospinning technique combining with hydrothermal method. Results show that the in-situ formed CoS x HNPs were completely covered by a layer of onion-like carbon, which can not only increase their conductivity but also buffer their volume changes during the charging/discharging processes. Interestingly, this type of unique configuration will raise the synergistic effect from excellent electrical conductivity of porous carbon nanofibers (PCNFs) and high specific capacitance of CoS x , endowing the hybrids to be an excellent electrode for high-rate performance supercapacitors. The resultant CoS x /C hybrid electrodes exhibit a high specific capacitance (496.8 F g −1 at 0.5 A g −1 ), superior rate capability (remaining 66.1% at 100 A g −1 ), and good cycling stability (over 89.0% after 2000 cycles). Besides, the assembled asymmetric supercapacitors of CoS x /C hybrids//PCNFs show high energy density (15.0 W h kg −1 at power density of 413 kW kg −1 ) and high cycling stability (over 80% after 2000 cycles). [ABSTRACT FROM AUTHOR]