Preparation And Research Of Layered Double Hydroxide Modified Cuprous Oxide Photocatalytic Fiber

Cuprous oxide（Cu₂O）has received widespread attention as a promising visible light semiconductor photocatalyst due to its narrow band gap,low toxicity,and low production cost.The photocatalytic activity of pure Cu₂O is relatively low.because the photogenerated electron-hole pair is easily recombined,and Cu₂O with different morphologies has a great influence on photocatalytic performance,and the powder photocatalyst is hard to recycle and has low reusability.Aiming at the deficiencies of Cu₂O,this paper introduces layered double hydroxides（LDHs）that can hold anions in its interlayer,and by NiFe-LDH modified Cu₂O with Z-heterojunction,and loaded on polyacrylonitrile（PAN）fibers,Improve the photocatalytic decolorization ability of the composite catalyst,and further improve its recyclability.Using scanning electron microscope（SEM）,X-ray diffractometer（XRD）,universal testing machine,electrochemical workstation,ultraviolet-visible absorption spectroscopy（UV-vis）and other test methods,Study the impact of the different morphologies of cuprous oxide,different molar ratio of Ni and Fe,different loading amount of photocatalyst on photocatalytic performance.The main research contents of this paper are summarized as follows:1.Cu₂O/PAN photocatalytic fibers with different morphologies have different photocatalytic performance,it can catalyze organic systems with high efficiency and have reusability.After the initial dye concentration is 15 mg/L,the dosage is 30 m L,the photocatalyst is 0.05 g,and the 500 W xenon lamp is irradiated for 120 min,the dodecahedral Cu₂O/PAN photocatalytic fiber has the highest degradation rate of methylene blue（MB）.It reached 94.75%,and the degradation rate was still as high as 85%after repeated use for 5 times,indicating that the photocatalytic fiber has a good degradation effect and reusability.2.The degradation of MB was used to evaluate the catalytic performance of photocatalysts with different molar ratios of Ni and Fe.After 120 min of visible light catalysis,the degradation rate of MB by dodecahedral Cu₂O was 32.7%,the degradation rate of Ni₂Fe₁-LDH was 45.8%,and the degradation rate of Ni₃Fe₁-LDH@Cu₂O was increased to82.0%.Finally,the optimal molar ratio of Ni and Fe was screened out to be 3:1.By studying its optical and electrochemical properties,the direct Z-type heterojunction photocatalytic mechanism is used to explain the reason for the enhancement of the photocatalytic performance of Ni₃Fe₁-LDH@Cu₂O.3.Evaluate the effect of different Ni₃Fe₁-LDH@Cu₂O addition on the performance of photocatalytic fiber.After 60 minutes of visible light irradiation,5%Ni₃Fe₁-LDH@Cu₂O/PAN has the best degradation effect on MB,reaching 91.7%.Its specific surface area is 76.3cm2.g-1 and has certain mechanical stability.after repeated use for 5 times,its photocatalytic effect is still as high as over 85%.The photocatalytic effect of5%Ni₃Fe₁-LDH@Cu₂O/PAN can reach high efficiency in a short time,laying the foundation for further industrial application.