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There are few researches on the application of multifunctional carbon quantum dots (CQDs) in analysis and detection. In this study, carbon quantum dots (CQDs) with dual‐function detection were synthesized by the one‐step hydrothermal method with citric acid as the carbon source and o‐phenylendiamine as the nitrogen source to detect Fe3+ and sunset yellow. The morphology of the prepared CQDs and the surface functional groups were characterized using TEM, FTIR, XPS, UV‐Vis spectroscopy, and fluorescence spectrophotometer. The results show that the morphology of CQDs is nearly spherical and well dispersed, with a particle size range of 1.24∼6 nm and the average particle size was 3.23 nm. The surface of the CQDs has hydrophilic groups, such as OH, −COOH and −NH2. CQDs exhibited good acid and alkali resistance, salt resistance, and photobleaching resistance under different conditions. The detection limits of CQDs for Fe3+ and sunset yellow were 1.52 μM and 0.812 μM, respectively. The recoveries of actual samples were 96.65 %∼104.85 % and 95.4 %∼104.55 %, with relative standard deviations (RSDs) of less than 6 %. Therefore, CQDs can be employed as dual‐function fluorescent probes in the practical detection of samples and have promising application prospects. [ABSTRACT FROM AUTHOR]

Radial-like ZnO structures were prepared using zinc sulfate (ZnSO4·7H2O) and zinc acetate [Zn(CH3COO)2·2H2O] as zinc sources by a facile template-free hydrothermal method in this paper. Structural and optical properties of radial-like ZnO structures are characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), UV-vis spectrophotometer and photoluminescence measurement (PL). It has been found that the distinct surface morphologies of radial-like ZnO structures grown by different zinc sources. Slim radial-like ZnO with a hexagonal wurtzite structure is grown by using ZnSO4·7H2O as zinc sources, whereas coarse radial-like ZnO with zincite structure is achieved by zinc acetate. The UV-vis absorption spectra of them both display an obvious and significant absorption in the ultraviolet region. The room temperature PL spectra of ZnO structures grown by two different zinc sources possess a common feature that consists of a strong ultraviolet (UV) peak and visible emission band. [ABSTRACT FROM AUTHOR]