The Design And Synthesis Of Nicotinic Acid Functional Copper Based Micro/nanomaterials And Their Catalytic Properties

In recent years,the metal micro/nano materials showed good performance in enhanced catalytic,surface enhanced Raman,surface plasmon resonance,fluorescence and other fields.Especially,multimetal nanoparticles system improves its catalytic performance which has caused high attention on the characteristics of science and technology.The properties of metal micro/nanomaterials are determined by a set of parameters,such as material composition,size,morphology and structure.We can control these factors to regulate the synthesis of metal micro/nanomaterials.The key factors of synthesis of metal micro/nanomaterials were the costs.In fact,copper or copper salt have been used instead of using noble metal nanoparticles as the catalyst in some reaction.We designed and prepared different shapes of copper-based micro/nanostructures materials by one pot methods and used them as the catalysts reduction of nitrophenol compounds.The morphology,composition and structure of sample were fully characterized by transmission electron microscopy?TEM?,scanning electron microscopy?SEM?,energy-dispersive X-ray spectroscopy?EDS?,electron paramagnetic resonance?EPR?,X-ray diff raction?XRD?and X-ray photoelectron spectroscopy?XPS?techniques.The copper based micro/nanostructures materials,using nicotinic acid functional synthesis method,were used as catalysts in reduction of nitrophenolic compounds by Na BH₄ solution,and their catalytic properties and recycling were researched.?1?A series of three-dimensional?3D?copper nicotinate hollow microstructures were fabricated by a one step method.The shape of the copper nicotinate hollow microstructures evolved from a hexagon,to an octagon and to a tetragonum,depending on setting time and concentrations of the reactants.The mechanism of the growth of the copper nicotinate hollow microstructures has also been investigated,which indicated that 3D copper nicotinate hollow microstructures were assembled by ultrathin copper nicotinate nano-sheets.The catalytic activities of the as-obtained copper nicotinate hollow microstructures for the reduction of 4-nitrophenol by sodium borohydride were examined.The catalytic activity of copper nicotinate hollow microstructures was greatly improved due to the hollow structure.?2?In this work,annular Au–Cu nicotinates were synthesized through a facile one-pot method.Cupric nitrate trihydrate,hydrogen tetrachloroaurate and nicotinic acid were used as the initial reactants;nicotinic acid was found to be an excellent ligand.Experimentally,the optimized ratio of the components was found to be Au:Cu:nicotinate close to 1:4:1.The shape of the assembled Au–Cu nicotinate rings can be readily controlled by changing the ratio of the reactants and the reaction time.The mechanism of growth of the Au–Cu nicotinate annular rings was also investigated;the results of the experiments indicate that the Au–Cu nicotinate annular rings were assembled from ultrathin nanosheets.The Au–Cu nicotinate rings exhibit excellent catalytic activity toward the reduction of nitrophenols?including 2-nitrophenol,3-nitrophenol,4-nitrophenol and 4-nitrothiophenol?by sodium borohydride in water.Importantly for their use as catalysts,the Au–Cu nicotinate rings can be recycled and exhibit good reusability.These results indicate that Au–Cu nicotinate rings are an effective catalyst for environmental wastewater treatment.?3?The investigation on the correlation between the performance and the shape of the micro/nanomaterials has caused the great attention of researchers.A facile and environment-friendly approach for synthesis of sea urchin CuAu nanospheres was reported.Copper nitrate,gold chloride acid,ascorbic acid and nicotinic acid were used as initial reactants,the results showed that ascorbic acid has better reductibility.CuAu nanospheres were used as catalyst for reduction of nitrophenol?4-NP?in Na BH₄ by uv-vis absorption spectroscopy to monitor the whole reaction process.The results show that the CuAu nano ball has good catalytic activity.?4?In this study,we designed a simple direct precipitate route to successfully synthesize the CuPd microrods and Cu AuPd nanoflowers.It was found that the CuPd microrods and CuAuPd nanoflowers were used as a catalyst in the borohydride reduction reaction of 4-nitrophenol?4-NP?,which was monitored by UV-vis absorption spectroscopy.Results demonstrated that with 0.2 M nicotinic acid generating CuAuPd nanoflowers showed a comparable catalytic performance,and the apparent rate constant is 0.0528 s^-1.Moreover,the stability and reusability of the catalyst were also investigated.High catalytic activity and ease of recovery from the reaction mixture by using filtration after several reuses without any significant loss of performance are additional eco-friendly attributes of this catalytic system.