Preparation And Properties Of Coordination Polymer-derived Carbon-based Composites

In recent years,with the excessive consumption of traditional fossil fuels and the worsening of environmental deterioration,environmental issues have increasingly attracted people's attention,which urges people to explore clean and sustainable energy alternatives and water purification materials.Among all kinds of clean energy,hydrogen has been drawn increasing attention due to its advantages such as inexhaustible source,low pollution,high energy density and high efficiency.Compared to traditional hydrogen production methods,photocatalytic decomposition of water to produce hydrogen is cleaner and more sustainable.In addition,4-nitrophenol(4-NP),as a persistent organic pollutant in agriculture,fuel and pharmacy,has a high chemical stability and water solubility,Which leads to its accumulated in water,and Because of its high toxicity and potential carcinogenicity,4-NP has caused serious damage to the environment and human health,hence,it is also necessary to seek a technology that can effectively deal with 4-NP wastewater.Besides,because of its complex molecular structure,long residence time in water,difficulty in natural degradation and wide distribution,the organic dye in water has become an important problem to be solved urgently.Based on the above analysis,the main contents of this article are as follows:1.With calcination,an efficient Cu2O composite material(Cu/Cu2O@NC)has been synthesized successfully with coordination polymer as precursor,which is constructed by Cu(II)metal ion as the center.In this composite material,Cu2O particles with a size of about 6-10 nm were dispersed evenly in the nitrogen doped mesoporous carbon matrix.After calcination,some coordinated nitrogen atoms were doped in the lattice of Cu2O and replace oxygen atoms,thus generating a large number of oxygen vacancies.In Cu/Cu2O@NC,the existence of oxygen vacancies has been confirmed by electron spin resonance(ESR)and X-ray photoelectron spectroscopy(XPS).Under visible light irradiation,Cu/Cu2O@NC exhibits excellent H2 production with the rate of 379.6 ?mol·h-1·g-1.Its photocatalytic activity affects organic dyes,such as Rhodamine B(RhB)and methyl orange(MO).In addition to photocatalysis,Cu/Cu2O@NC also exhibited significant catalytic activity for 4-NP reduction conversion with in presence of sodium borohydride(NaBH4).The conversion efficiency reaches almost 100%in 250 s with the dose of Cu/Cu2O@NC as low as 5 mg.The outstanding H2 production and organic pollutants removal are attributed to the oxygen vacancy.We expect that Cu/Cu2O@NC will find its way as a new resource for hydrogen energy as well as a promising material in water purification.2.To obtain a magnetic composite material for water treatment,a Ni based composite material with nitrogen doped mesoporous carbon as matrix(Ni@NC)has been synthesized with coordination polymer as precursor,which is constructed by Ni(II)metal ion as the center.In this composite material,Ni nanoparticle with the size about 3 to 5 nrn dispersed evenly in nitrogen doped mesoporous carbon matrix.Ni@NC exhibits striking catalytic activity in reductive conversion of 4-NP to 4-aminophenol(4-AP)with the existence of NaBH4.The conversion efficiency reaches almost 100%in 160 s with the dose of Ni@NC as low as 5 mg.After 8 successive cycles,the reduction efficiency still retains above 99%.In addition,Ni@NC also possesses excellent activity in catalytic reduction of organic dyes,such as RhB,MO and methylene blue(MB).Due to its large surface area and suitable pore size,Ni@NC also possesses adsorption removal property towards tetracycline(TC)and Cr2O72-.Magnetic measurement reveals ferromagnetic character of Ni@NC,which facilitates its magnetic separation from the treated samples.All these merits make Ni@NC a promising multifunctional environmental material in waste water treatment.