Preparation And Photocatalytic Performance Of Novel Copper-based Coordination Polymers And Their Derivative Composite

Industrial wastewater containing various organic pollutants poses a hazard to human health and ecological environment.Photocatalysis removes low-concentration pollutants without the need for secondary treatment.Among many photocatalysts,it is a promising direction to design and construct photocatalysts with high chemical stability,non-toxic,cheap,economical,environment-friendly and high catalytic activity.In recent years,coordination polymers（CP）,consisting of metal centers and coordination organic connectors,are emerging porous materials that have attracted widespread attention for their highly adjustable pore size and shape,various structures,and many functions.Cu-CP containing Cu metal ions was synthesized with N,N’-II（3-pyridine）hexodiamide（3-dpha）and 1,4-naphthalene-dicarboxylic acid（1,4-H₂NDC）in a simple hydrothermal synthesis method.Cu-CP was found to have a good photodegradation rate for steelnut red,crystalline purple and methyl orange by UV catalyzing degradation of common organic dyes.Furthermore,most of the developed photocatalysts are powders,which leads to serious recontamination and recycling problems.From this point of view,membrane materials are much needed,but this is often accompanied by problems of photodegradation and solution stability.As a classical photocatalyst,titanium dioxide has the ability to degrade organic dyes by photocatalysis.Unfortunately,the photocatalytic efficiency of pure titanium dioxide is small due to its large band gap.In this regard,the adoption of structural and chemical modifications to improve the photocatalytic activity of TiO₂,particularly metal doping,is considered an effective method to improve the photocatalytic efficiency of titanium dioxide.It is a promising method to synthesize transition metal doped titanium dioxide with transition metal CPs.In addition,CPs are used as sacrificial precursors to form structures containing uniform distribution of elements,large specific surface area,highly dispersed active sites,and controllable structures.Here,a high purity Cu@TiO₂ membrane was prepared by cryop Cu-CP annealing and simple filtration.Cu@TiO₂membrane showed good stability in solution.We investigated the photodegradation efficiency of the membrane as a photocatalyst.The membrane has good selective and repeatable photodegradation properties for crystalline purple organic dyes.In addition,because ammonium tetramolybdate（NH₄）₂MoS₄ begins to break down into catalytic molybdenum disulfide MoS₂ at 350℃,molybdenum disulfide has its desirable property,a direct band gap,which allows the material to convert photons into electrons,and vice versa,making molybdenum disulfide a good candidate for use in optical devices.The material is also abundant,inexpensive and non-toxic.Molybdenum disulfide,as copper ion chelating agent,can corrode the surface of Cu,resulting in large specific surface area and highly dispersed active sites.Here,the Cu@MoS₂ membrane is synthesized in the same way and has good stability in solution.By exploring the photodegradation efficiency of the membrane as a photocatalyst,the membrane has good selective and repeatable photodegradation properties for crystalline purple and steelnut red organic dyes.