Inverse-opal structured TiO_(2) regulating electrodeposition behavior to enable stable lithium metal electrodes

Lithium metal anode is almost the ultimate choice for high-energy density rechargeable batteries, but its uneven electrochemical dissolution-deposition characteristics lead to poor cycle stability and lithium dendrites safety problems. The fundamental solution to the problems is to interfere electrodeposition process of lithium metal so that it can be carried out reversibly and stably. In this work, an inverse-opal structured TiO2membrane with a thickness of only ~1 μm is designed to regulate the electrodeposition behavior of lithium metal, in which the ordered channels homogenize mass transfer process, the anatase TiO_(2)walls of the ion channels reduce desolvation barrier of solvated lithium-ions, and the spherical cavities with a diameter of ~300 nm confine migration of the adsorbed lithium atoms during electrocrystallization to diminish overpotential of lithium. These systematic effects cover and essentially change the whole process of electrodeposition of lithium metal and eliminate the possibility of lithium dendrite formation. The as-obtained lithium metal electrode delivers a Coulombic efficiency of 99.86% in the 100th cycle, and maintains a low deposition overpotential of 0.01 V for 800 h.

Preparation and adsorption property of novel inverse-opal hierarchical porous N-doped carbon microspheres

The design of pore structure is the key factor for the performance of porous carbon spheres.In this wo rk,novel micron-sized colloidal crystal microspheres consisting of fibrous silica(F-SiO_(2)) nanoparticles are firstly prepared by water-evapo ration-induced self-assembly of F-SiO_(2) nanoparticles in the droplets of an inverse emulsion system to be used as sacrificial templates.Acrylonitrile(AN) was infiltrated in the voids of the F-SiO_(2) colloidal crystal microspheres,and in-situ induced by ^(60)Co γ-ray to polymerize into polyacrylonitrile(PAN).After the PAN-infiltrated F-SiO_(2) colloidal crystal microspheres were carbonized and etched with HF solution,novel micron-sized inverse-opal N-doped carbon(IO-NC) microspheres consisting of hollow carbon nanoparticles with a hierarchical macro/meso-porous inner surface were obtained.The IO-NC microspheres have a specific surface area as high as 266.4 m^(2)/g and a molar ratio of C/N of 5.They have a good dispersibility in water,and show a high adsorption capacity towards rhodamine B(RhB) up to 137.28 mg/(g microsphe re).This work offers a way to obtain novel micron-sized hierarchical macro/meso-porous N-doped carbon microspheres,which opens a new idea to prepare high-performance hierarchical porous carbon materials.

Enhanced visible light absorption of Bi_(2)WO_(6)/SiO_(2) with abundant adsorbed oxygen for the degradation of organic pollutant

Heterogeneous photocatalysts exhibit high catalytic efficiency in the degradation of pollutants,but their stability and repeatability is not very good and requires high structural matching.Simply by nanosizing the pure Bi_(2)WO_(6)(BWO)photocatalyst without constructing a heterojunction,there is a significant improvement in its performance,with an enhancement effect of about 2.3 times(99.43%).The high photocatalytic degradation efficiency of the material can be attributed to the enhanced light absorption effect brought by the three-dimensional inverse-opal structure SiO_(2)(IS)and the abundant surface adsorbed oxygen generated after the formation of Si–O–W bonds.In addition,the introduction of IS greatly increases the surface area of nanostructured BWO,which accelerates the charge transfer process,while the adsorbed oxygen promotes the participation of·O^(2−) in the photocatalytic reaction,thereby accelerating the consumption of photo-generated electrons and ultimately improving the separation of charge carriers.Furthermore,the matched photonic bandgap further improves the absorption and utilization of light of the material.In this work,we constructs Si–O–W bonds to obtain inverse-opal SiO_(2)/Bi_(2)WO_(6) with uniformly growth of pure phase nano BWO,which provides a feasible strategy for the preparation of high-performance pure-phase photocatalysts.