Preparation And Performance Of CuO/TiO₂ And Co₃O₄/CNTs Transition Metal Oxide Composites

With the continuous development of science and technology industry and the continuous growth of social demand,energy shortage and environmental pollution have become two major problems facing human society,and the development of renewable energy and electrochemical energy utilization technology is an effective strategy to solve this problem.Photocatalytic technology can directly use solar energy to produce fossil fuels,degrade pollutants and make organic synthesis,which has attracted widespread attention.However,the semiconductor material represented by titanium dioxide has a wide band gap,the utilization rate of visible light is low,and the photoelectrons and cavities are prone to compounding,which limits its development and utilization in the field of photocatalysis.In photocatalyst design engineering,the composite material using transition metal oxide oxides to construct heterogeneous junction structure can significantly inhibit the compounding rate of electron cavity and expand the absorption range of light,which proves to be one of the most effective methods for preparing photocatalysts with excellent performance.Lithium-ion battery has become the most promising secondary battery because of its environmental friendliness,fast charge and discharge performance,high energy density and stable cycle life,and is widely used in various fields.Graphite as the most commercial application value of single-electronic anode material?Li C₆?,its maximum theoretical capacity of 372 m Ah/g,in order to meet the growing demand for energy storage devices,the development of multi-electronic anode material is the main research direction of the next generation of lithium-ion batteries,and the transition metal oxides due to its high theoretical capacity?2 to 2.5 times commercial graphite material?has become the main focus of attention.This paper prepares Cu O/Ti O₂ composite materials by means of high temperature calcination,chemical stripping and electrostatic attraction,analyzes the structure and morphology of composite materials by means of XRD,XPS,SEM,TEM,EDX and XAFS characterization,and reveals the optical properties of composite materials by means of UV,PL,TRPL,EIS and Mott-Schottky characterization.As tert-butyl hydroperoxide?TBHP?an oxidant,300w xenon lamp as the light source,Cu O/Ti O₂ composite material as the catalyst,photocatalytic styrene reaction,the effect of calcination temperature,solvent,load and other conditions on photocatalytic activity was investigated.Under the optimized condition of the temperature of 450°C,the solvent isacetylene,the load of Cu is 2.5 wt.%,the conversion rate of styrene is 40%,the selectivity of benzene aldehyde is 80%,and the photocatalytic activity is stable in the circulatory reaction,and the reaction mechanism of Cu O/Ti O₂catalyst photocatalytic oxidation styrene is finally estimated.This paper prepared Co₃O₄/CNTs composite materials of carbon nanotube encapsulation of cobalt dioxide nanoparticles by template and chemical vapor deposition,and analyzed the structure and morphology of composite materials by means of XRD,SEM,TEM,HRTEM,HAADF STEM,XPS representation,and tested the electrochemical properties of composite materials for lithium-ion batteries.The situ TEM method reveals the lithiation process and storage mechanism,this special structure composite material shows stable cycle performance and high multiplier performance,after 200 times at the current density of 0.5 C,the discharge ratio capacity still reaches 850 m Ah/g,and the discharge ratio capacity reaches 694 m Ah/g at 2 C current density.