Preparation And Characterization Of Novel Micro-Nano Molybdenum Oxide Materials

Micro-nano metal oxides have attracted ever increasing interest due to their unique optical,electronic properties and potential applications in maicro-nano devices.Among them molybdenum oxides are representative materials which have found important applications in the fields of opto-electronic field,catalysis and biological medicine.In this thesis,we fabricated a series of micro-nano molybdenum oxides via facile microwave-assisted method.The morphologies and size of these materials can be conveniently controlled by tuning various experimental conditions including reaction time,temperature and the type of surfactants.These as-synthesized micro-nano materials were thoroughly characterized and their cell toxicity and adsorption as well as optical properties were investigated.Specifically,the thesis is divided into the following parts:1.Introduction of the research background and literature review.2.In this chapter,In this thesis,a series of micro-nano molybdenum oxides were fabricated via facile microwave-assisted method by controlling experimental conditions such as reaction time,temperature and the type of surfactants.As a result,micro-nano molybdenum oxides of hexagonal phase(h-MoO,)with varied morphologies(cubes,spheres,fibers and hexagonal prisms,etc.)and sizes(micro-nano)were obtained and thoroughly characterized by TEM,SEM,XRD and various spectroscopic methods.3.The cell toxicity and optical properties of these as-synthesized micro-nano materials were preliminarily investigated.The water-soluble nano molybdenum oxides exhibited fair Localized surface plasmon resonance(LSPR)bands in the near infrared region with maximum absorption peaks at?750 nm,indicative of potential in photo thermal therapies.Preliminary cell viability results indicated these nano materials were strongly toxic to Hela cells,implying possible applications in treating malign tumor cells.In addition,insoluble micro molybdenum oxide cubes exhibited strong optical limiting effects.4.The micro molybdenum oxide cubes were found to show strong adsorption to organic dyes,with a maximum theoretical adsorption capacity of 434.7mg/g to methylene blue,significantly surpassing traditional adsorption materials such as montmorillonite clay and Palygorskite.The results indicate the micro molybdenum oxide cubes may be great potential in treating waste water with organic pollutants.The adsorption thermodynamics and kinetics were thoroughly investigated,which showed that the adsorption of these micro molybdenum oxide cubes to methylene blue can be described by Langmuir isotherm,and the kinetics can be best fitted with a pseudo second order equation.The ? G? values of the adsorption range from-14.1 kJ/mol to-10.7 kJ/mol,implying physical adsorption dominates the interaction between these micro molybdenum oxide cubes and methylene blue.