Study On The Preparation And Properties Of Activated Carbon Fiber Networks Coated With Cu₂O

Resolving energy and environmental problems as well as seeking social sustainable development have gradually become the consensus of mankind in the 21st century.With the exploitation and research on various new energies,it is particularly important to store and use energy more effectively and build decentralized energy,among which electrochemical energy storage has received the biggest concerns.Meanwhile,the awareness of people-oriented environmental protection drives people to actively undertake environmental pollution control.Carbon materials and semiconductors stand out from the crowd in the exploration of many advanced materials,their rich pore structures have long been applied to physical adsorption.In recent years,their high specific surface area and electric double layer energy storage principle have been newly applied in electrode materials,which promote the development and application of flexible devices.Owing to the intrinsic special band structure,the semiconductor materials'research achievements in the fields of photoelectric conversion and photocatalytic degradation is are also remarkable.In this paper we designed a composite system with activated carbon as the substrate and then coating with cuprous oxide film.The flexibility of the composite system,photocatalytic properties and photocatalytic performance as well as decolorization performance were investigated.We chose commercially available pure cotton fabric as raw material and prepared activated carbon fiber networks?ACFN?by high-temperature carbonization method.ACFN followed the woven structure of cotton fabric and could be repeatedly twisted and bent with certain tensile properties.Cu₂O was coated on the surface of ACFN by electrochemical deposition and hydrothermal method,the Cu₂O thin film was affected by the pH of deposition solution,electrolyte temperature,deposition time,etc.Under the conditions of pH=9,T=60?and deposition time of 10 min,the pure Cu₂O thin film with dense ACFN surface could be obtained,whose crystal grain was about 0.5 um and pyramidal in shape with high crystallinity.Cu₂O thin film fabricated by hydrothermal method was affected by the concentration of reactants,temperature,reaction time,etc.Under the conditions of copper acetate concentration of 0.05 M and temperature of 180?,Cu₂O thin film coated with uniform and dense ACFN surface could be obtained.ACFN/Cu₂O composite are sensitive to optical power and light wavelength,they can produce some photocurrent under weaker light intensity,and adsorb red light which is the longest wavelength in visible light.As the optical power increased from 5 mW/cm² to 100mW/cm²,the photocurrent density increased from 0.1 mA/cm² to 1.2 mA/cm².The photocurrent density of ACFN/Cu₂O composite are 0.02 mA/cm² and 0.25 mA/cm²,respectively under the blue and red light irradiation with the sime optical power of 20 mW/cm².After stretching about20%,the photoelectric response of ACFN/Cu₂O composite remained good and the photocurrent density increased by nearly 10%.After 180 repeated intermittent illumination tests,the photocurrent density of the composite stabilized at 0.15 m A/cm².ACFN/Cu₂Ocompositecouldconductphotocatalysisandphysicaladsorption simultaneously when used to decolorize methyl orange,demonstrating excellent decolorizing effect of methyl orange solution.The decolorization rate of methyl orange reaches to 96.2%on the first use of the ACFN/Cu₂O composite.Increasing the using time reduces the degradation rate,which remained at 81.9%after reuse for ten times.The decolorization rate was as high as96.2%after 4 hours of initial light and remained at 81.9%,and the decolorization rate remained at 81.9%after ten repeated uses,showing good reusability;the decolorization rate of methyl orange solution at lower concentration was faster,the decoloration rate reached more than 80%at the first 1.5 h when the concentration was not higher than 10 mg/L,but excessively high concentration could reduce the decolorization efficiency of ACFN/Cu₂O composite.The decoloration rate of ACFN/Cu₂O composite was only 41.2%after decolorization of methylene blue solution for 4 h.After adding H₂O₂,the decolorization rate significantly improved to 93.4%after 4 h for the change of the degradation mechanism.This paper explored the surface deposition of semiconductor materials on activated carbon fabric,which provides more possibilities for the functionalization of activated carbon materials.The composite system described in this paper also provides a new concept and method for the construction of photovoltaic devices and the treatment of environmental pollution.