The Preparation And Analytical Application Of Photo-functionalized Nanomaterials

With the great advancement of nanotechnology,a series of nanomaterials with unique optical properties（photofunctional nanomaterials）have been successfully prepared and widely used in the fields of bioanalysis and sensing,environmental monitoring and decontamination,energy conversion and storage,disease diagnosis and treatment,while certain challenges remain.Developing new synthetic technologies for these photo-functional nanomaterials and combining materials with different functions are very important for both fundamental research and practical application.Surrounding fluorescence and photothermal nanomaterials,this dissertation presents systematic research about their preparation and application in the fields of anti-counterfeiting,sensing,analysis,isolation,and purification.The main research results are summarized as follows:1.Aiming at the poor stability of perovskite quantum dots,inorganic perovskite quantum dots were embedded into polystyrene（PS）gel via non-polar organic polymers polymerizing under mild conditions to form organic-inorganic composite materials significantly improved the light,heat,and humidity stability of Cs Pb X₃（X=Cl,Br,I）.The compound gels with different fluorescence emissions（blue,green,and red）were used as the three primary color quantum dot inks,and the emission peaks were continuously controlled in the wavelength range of 450-700 nm.Pre-polymerized polystyrene is used as auxiliary ink to adjust the viscosity of fluorescent ink,which was used for multi-color fluorescent inkjet printing to realize the application of the perovskite quantum dots in patterning and fluorescent anti-counterfeiting.2.In order to further improve the stability of perovskite fluorescent materials,a novel one-pot green synthesis strategy has been developed for the large-scale synthesis of the perovskite-like fluorescent material Cs₄Pb Br₆ with high purity in DMF.The synthesized Cs₄Pb Br₆ has excellent fluorescent properties(λ_em=520 nm,FWHM=20 nm)and thermal stability（200℃）,and the solvent can be reusedmultiple times.The fluorescence intensity of the Cs₄Pb Br₆/PDMS composite is strongly dependent on temperature.Owing to this merit,a luminescent sensor using the Cs₄Pb Br₆/PDMS composite was fabricated for the fluorescence sensing of temperature,which shows excellent responsiveness（30-200℃）and linear correlation（R²=0.998）.3.To improve detection sensitivity and reduce background interference,a facile photothermal paper sensor for the detection of hydrogen sulfide（H₂S）was constructed and displayed satisfactory performance.We prepared Au@Ag coll-shell NPs with the hot injection method,in which the LSPR wavelength could be significantly modulated by the presence of sulfide ion(S^2-)via the formation of Ag₂S on the surface of Au@Ag NPs.The photothermal effect was significantly enhanced under the irradiation of 650-nm laser.The visualization detection limit of 12.8 ng/L was achieved for gaseous hydrogen sulfide.4.To improve water purification performance of photothermal materials,an efficient solar steam generation system was constructed by embedding photothermal responsive plasmonic CMA NPs into a robust porous PDMS matrix,which was fabricated through gas diffusion guided 3D porous structure formation,followed by surface coating with in situ acrylic acid polymerization.The afforded photothermal materials displayed a solar steam generation rate of3.824 kg·m^-2 h^-1 with an energy efficiency of 96.6%under one-sun irradiation.Furthermore,the designed free-floating photothermal materials exhibits excellent mechanical properties（70%compress）and satisfactory tolerance to harsh conditions（strong acid,strong base,strong oxidants,and high salinity）.