Design Of Metal Coordination And Its Application In Environmental Chemistry

With the accelerating of urbanization process,environmental pollution,especially the discharge of pathogenic microorganisms or new refractory pollutants caused by human activities,such as agriculture,medicine and industrial production which can generate a large number of toxic and harmful substances that enter the ecological environment system in various ways.At present,the analysis and post-processing of environmental pollutants still highly rely on complicated pre-treatment,high-precision large-scale equipment and time-consuming procedures.It is difficult to realize the realtime detection,meanwhile,it is also easily interfered by a complex environmental system and geographical environments.Moreover,post-treatment is always limited by complicated processes,making it difficult to realize the determination of environmental pollutants with fast speed,high efficiency and recyclability.Due to all these drawbacks,it is of great significance to establish a high-analysis sensing platform with highsensitivity,develop excellent environmental pollutants post-treatment strategies based on new environmentally friendly materials,establish a new mechanism on the degradation of toxic and harmful refractory pollutants and apply them in the environmental chemistry field.In recent years,metal coordination chemistry is showing its advantages gradually in the field of environmental chemistry.It can produce enhanced optical and electrochemical response or excellent adsorption and catalytic performance due to the diversity of the combination between metallic centres and bridging organic linkers,as well as the simultaneousness of the two parts targeting on environmental substances.In this research,we focus on designing novel sensing platforms and post-treatment strategies for environmental target substances based on the fundamental principles of metal coordination chemistry,including three parts:(1)Metal reversible competitive coordination;(2)Metal adjustable coordination;(3)Metal destructive coordination.This article was divided into four chapters as followes: Chapter 1.OverviewIn this chapter,we begin with the background of metal coordination chemistry and its development in environmental chemistry.Moreover,research of other scholars has proved that metal coordination chemistry is widely used in the identification of environmental target substances and the post-treatment of environmental pollutants.Finally,we proposed the innovations of our methods that have been established at present.Chapter 2.Based on metal reversible competitive coordination to design of alizarin Red(AR)-Tb3+ Complex as Ratiomectric Colorimetric and Fluorescent Dual Probe for the Smartphone-Based Detection of Anthrax BiomarkerIn this work,we have developed a novel dual-sensing mode probe for detecting anthrax biomarker(dipicolinic acid,DPA)based on the reversible competitive coordination of DPA and the Alizarin Red(AR)-Tb3+ complex in boric acid-borate buffer solution.UV-vis titration experiments demonstrated that AR and Tb3+ ions formed a 3:1 coordination pair in buffer.In the absence of DPA,the as-formed AR-Tb3+ complex showed a mauve color and a weak orange fluorescence under an ultraviolet(UV)lamp.However,the subsequent addition of DPA to the complex solution well destroy the coordination of AR-Tb3+,resulting in the formation of DPA-Tb3+.As a consequence,the color of the solution changed from mauve to yellow,in the meantime,the bright green fluorescence of DPA-Tb3+ turns on,which constitutes a new mechanism for ratiometric colorimetric and fluorescent dual-model sensing of DPA.Implanted a smartphone with easy-to-access color-scanning APP,this dual-sensing method could be further applied as reliable scanometric assays for rapid and on-site visible detection of DPA directly.With the method we developed,the sensitive and selective detection of DPA released from bacterial spore can be realized easily.Chapter 3.Based on adjustable coordination to rational design of magnetic infinite coordination polymer core-shell nanoparticles as recyclable adsorbents for selective removal of anionic dyes from colored wastewaterIn this work,novel magnetic infinite coordination polymer Fe3O4@Tb/AMP coreshell nanoparticles were rationally designed and fabricated as recyclable adsorbents for selective removal of anionic dyes from colored wastewater based on adjustable coordination.The core-shell nanoparticles used in this study are composed of two components: the shell is the supramolecular infinite coordination polymers(ICPs)network formed by terbium ions(Tb3+)and adenosine 5'-monophosphate monohydrate(AMP)ligands and the core is the Fe3O4 nanoparticles which are encapsulated into the ICP network by the self-adaptive inclusion process.Parameters that influenced the adsorption process,such as solution p H,salt concentration and adsorbent dosage were investigated.Under the optimal conditions,this nano-adsorbent exhibited rapid adsorption feature(almost 96% dye removal in 5 min)and the adsorption isotherm data fitted quite well with the Langmuir model with an estimated maximum adsorption capacity of 357.14 mg g-1 for Alizarin Red and 909.09 mg g-1 for Congo Red at 298 K.This capacity could be further enhanced at the higher temperatures.In addition,the Fe3O4@Tb/AMP core-shell nanoparticles could be regenerated by a simple salt/ethanol-washing method and used with high recyclability over five cycles.With the magnetically separable Fe3O4@Tb/AMP core-shell nanoparticles as adsorbents,selective removal of toxic anionic dyes from colored wastewater could be realized directly,which is important for the sustainable development of dye contaminated wastewater treatment technology.Chapter 4.Based on metal destructive coordination to design of ultra-small Co Ox/GO catalyst supported on ITO glass by electrochemical post-treatment of redox-active infinite coordination polymer: An efficient and portable reactor for real-time monitoring catalytical oxidative degradation of colored wastewaterIn this work,we have developed a novel method for preparing Co Ox/GO catalyst supported on ITO glass by electrochemical post-treatment of redox-active infinite coordination polymer(ICP){Co(3,5-dbsq)(3,5-dbcat)(bix)} nanoparticles based on metal destructive coordination.Firstly,highly dispersed Co Ox nanoparticles or Co Ox/GO nanocatalyst with ultra-small size and narrow size distribution(1.42 ± 0.34 nm or 1.21 ± 0.28 nm)were in-situ generation on ITO glass after electrochemical polarizing ICP coated ITO glass at-1.1 V for 1000 s in 0.10 mol L-1 KCl.Graphene oxide(GO)were mixed with ICP to obtain ITO supported Co Ox/GO catalyst with higher electron transport rate and enhanced stability.The catalytic activity of this Co Ox/GO catalyst was testified by looking at the degradation efficiency of methylene blue(MB)via advanced oxidation process in the presence of oxone,and the mechanism of the degradation process was explored.Under the optimal condition here,the enhanced catalytical oxidative degradation of dye solution could be achieved easily.100% MB(2.0 m L,20 mg L-1)could be decomposed within 4.0 min at 60?,which is found better than other Co Ox catalysts.The Co Ox/GO exhibited much lower activation energy,high catalytic performances and excellent recyclability.With this kind of ITO glass as elements,a portable reactor was constructed for the first time.By incorporating a UV/Vis spectrometer,real-time monitoring of the catalytic degradation of colored wastewater from textile and cosmetic industry could be realized by this reactor directly,which is of great importance for deveolping online monitoring instruments,analyzing information and optimizing process control during industrial wastewater treatment.