A stable and humidity resistant NH3 sensor based on luminous CsPbBr3 perovskite nanocrystals

Recent years, sensors based on perovskite nanomaterials have become one of the most interesting fields while their instability remains as one of the major obstacles for further advancement. In this work, for the first time, a facile and controllable strategy was proposed for in-situ growth of stable CsPbBr3 nanocrystals in SiO2 network on poly (vinylidene fluoride) membrane. The formation of SiO2 network was triggered by the fast hydrolysis of (3-aminopropyl)triethoxysilane as the precursor. Characterization results including UV-vis, FTIR, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) indicate successful formation of CsPbBr3-SiO2 nanocomposites. With the protection from SiO2 network, the fluorescence intensity of CsPbBr3 nanocrystals maintains 88.11% of initial intensity after 104 days in ambient environment and is stable during the humidity test (RH = 90%, for 30 min). CsPbBr3-SiO2 nanocomposite based membrane can be applied as fluorescent sensors for NH3 determination in high concentration range based on fluorescence quenching, which shows good linearity, accuracy, precision, and specificity toward NH3 over common organic vapors.