Preparation and application in Fe(Ⅲ)detection of nitrogen phosphorus co-doped sugarcane bagasse carbon quantum dots
In situ N and P co-doped carbon quantum dots(N/P-CDs)were prepared by a one-step hydrothermal method using biomass sugarcane bagasse as carbon source and diammonium dihydrogen phosphate as N and P sources.The optimal preparation conditions for N/P-CDs were obtained through single factor experiments with the relative fluorescence intensity of N/P-CDs as an indicator.The N/P-CDs were characterized by fluorescence spectrophotometer,XRD,UV-Vis,FTIR,AFM,and transient/steady-state fluorescence spectrometer for analyses on morphology,structure and fluorescence properties,and then applied for aqueous Fe3+[Fe(Ⅲ)]detection.The results showed that,under the conditions of m(diammonium dihydrogen phosphate)/m(sugarcane bagasse)=0.8,reaction temperature 260℃,reaction time 12 h,and feed amount(total mass of diammonium dihydrogen phosphate and sugarcane bagasse,the same below)2.16 g,the N/P-CDs obtained exhibited the highest relative fluorescence intensity,with the particle height mainly distributed between 0.2~0.7 nm,width approximately 9.7 nm,the absolute quantum yield reaching 14.6%,and the average fluorescence lifetime about 12.02 ns.The N/P-CDs displayed excellent fluorescence performance,exhibiting blue fluorescence under UV irradiation at a wavelength of 365 nm,with maximum excitation wavelength of 330 nm and emission wavelength of 407 nm.The N/P-CDs displayed strong specific fluorescence quenching effect in the presence of Fe3+,indicating selective aqueous Fe3+detection.