Efficient aerobic oxidative desulfurization via three-dimensional ordered macroporous tungsten-titanium oxides

A series of three-dimensional ordered macroporous(3 DOM)W-TiO_(2)catalysts have been prepared through a facile colloidal crystal template method.The prepared materials characterized in detail exhibited enhanced catalytic activity in aerobic oxidative desulfurization process.The experimental results indicated that the as-prepared materials possessed excellent 3 DOM structure,which is beneficial for the catalytic activity.The sample 3 DOM W-TiO_(2)-20 exhibited the highest activity in ODS process,and the sulfur removal can reach 98%in 6 h.Furthermore,the oxidative product was also analyzed in the reaction process.

Enhanced rate capability and mitigated capacity decay of ultrahigh-nickel cobalt-free LiNi_(0.9)Mn_(0.1)O_(2) cathode at high-voltage by selective tungsten substitution

Owing to the further requirement for electric vehicle market, it is appropriate to lower the cost and improve the energy density of lithium-ion batteries by adopting the Co-free and Ni-rich layered cathodes.However, their practical application is severely limited by structural instability and slow kinetics. Herein,ultrahigh-nickel cobalt-free LiNi_(0.9)Mn_(0.1)O_(2) cathode is elaborate designed via in-situ trace substitution of tungsten by a wet co-precipitation method following by high-temperature sintering. It is revealed that the in-situ doping strategy of high valence W^(6+) can effectively improve the structure stability by reducing irreversible phase transition and suppressing the formation of microcracks. Moreover, the transformed fine particles determined by W-doping can facilitate the kinetic characteristics by shortening Li^(+) diffusion paths. As expected, 0.3 mol% W-doped LiNi_(0.9)Mn_(0.1)O_(2) cathode exhibits a high specific capacity of 143.5 mAh/g after 200 cycles at high rate of 5 C in the wide potential range of 2.8-4.5 V, representing a potential next-generation cathode with low-cost, high energy-density and fast-charging capabilities.

Multiscale control of MnO_(2) growth via[WO_(6)]-perturbed[MnO_(6)]assembly toward a favorable balance between capacitance and rate performance

Although pseudocapacitive manganese dioxide(MnO_(2))integrates the high-power merit of carbonaceous materials with the high-energy merit of battery-type materials,it still has a long way to go in achieving a more satisfactory balance of higher energy and power density,and in decoupling the relationship of structural characteristics with energy storage performance.To realize such goals,a bottom-up[WO_(6)]-perturbed[MnO_(6)]assembly strategy has been developed here due to their similar structure,yet mismatched lattice parameters.This facile protocol is capable of finely controlling the morphology and crystal structure of MnO_(2)by adjusting its internal[WO_(6)]concentration.Therefore,the as-prepared W_xMnO_(2)is treated as an ideal platform to scrutinize the correlations of the structure with the energy storage performance.The operando Raman spectra and finite element analysis have fully demonstrated the superiority of the locally ordered defects-enriched structure of W_(0.02)-MnO_(2),which could reach a favorable balance between the ion diffusion equilibrium time and the number of active sites.As a result,the W_(0.02)-MnO_(2)is able to deliver a high capacitance of 292 F·g^(-1)at a current density of 1 A·g^(-1)and a remarkable rate performance with a 60%capacity retention at a current density of 50 A·g^(-1).The further unveiled structure-performance relationship provides a guideline for the design of better pseudocapacitive energy storage devices.

Preparation and laser properties of Yb^3＋-doped microstructure fiber based on hydrolysis-melting technique

The Yb^(3+)-doped silica glass was prepared by the Si Cl_4 hydrolysis doping and powder melting technology based on high frequency plasma. The absorption and emission characteristics of the Yb^(3+)-doped silica glass are studied at room temperature. The integrated absorption cross section,stimulated emission cross section and fluorescence lifetime are calculated to be 8.56×10~4 pm^3,1.39 pm^2 and 0.56 ms,respectively. The Yb^(3+)-doped microstructure fiber(MSF) was also fabricated by using the Yb^(3+)-doped silica glass as fiber core. What's more,the laser properties of the Yb^(3+)-doped MSF are studied.

Hybrid of Quaternary Layered Double Hydroxides and Carbon Nanotubes for Oxygen Evolution Reaction

Highly active electrocatalysts based on Layered Double Hydroxides(LDH)towards oxygen evolution reactions(OER)are required for the applications of renewable energy-conversion technology.The improvement of conductivity and electron-transporting capability for LDH materials remains an enormous challenge yet.Here,we synthesized carbon nanotube supported quaternary FeCoNiW-LDH ultrathin nanosheets with 1 nm thickness via one-pot hydrothermal methods,which exhibit enhanced OER activity due to the synergistic effect of modified CNTs and doped W^6+onto LDH nanosheets catalysts.The loaded carbon nanotubes can directly result in the improved conductivity.In addition,W^6+doping in LDH can modify the electronic structure and further enhance the conductivity of electrocatalysts.FeCoNiW-LDH/CNT exhibits a small overpotential(258 mV)at a current density of 10 mA·cm^–2 and low Tafel slope(41 mV decade^–1)towards OER in alkaline solutions,outperforming the noble metal RuO2 catalysts.

Dual modulation of morphology and electronic structures of VN@C electrocatalyst by W doping for boosting hydrogen evolution reaction

Developing high-efficiency and robust durability electrocatalyst for hydrogen evolution reaction(HER)in water electrolysis functions as a crucial role for the construction of green hydrogen economy,herein,ultrafine W-doped vanadium nitride nanoparticles anchored on N-doped graphitic carbon framework(WVN@NGC)are synthesized through a one-step simple pyrolysis protocol.Owing to the enlarged catalytically active sites,enhanced electrical conductivity and optimized electronic structure,the resultant VN/WN@NGC delivered the prominent HER performance with overpotentials of 143 mV and 158 mV at10 mA/cm^(2) in acid and alkaline media,respectively,accompanied by the long-term stability for at least50 h.This work highlights a novel strategy for a metal-triggered modulation of nitride-based HER electrocatalyst for sustainable energy conversion device.