High-gravity-driven process intensified approach toward Mn2+ doped Zn2GeO4 nanophosphors for deep-ultraviolet detecting

Deep-ultraviolet (DUV) light devices are receiving widely attention due to their potential use in sterilization and water purification , in particularly, during the COVID-19 pandemic. Photoluminescence detectors that demonstrate the existence of DUV light invisible to our eyes are of importance. Herein, we propose a process intensified approach via high-gravity reactive precipitation combined with hydrothermal synthesis for production of Mn 2+ doped zinc orthogermanate (Zn 2 GeO 4 : Mn 2+ ) nanophosphors for deep-ultraviolet detecting. The rotating packed bed (RPB) was used as the reactor for process intensification of the reactive precipitation and the whole processing time was significantly reduced. The Zn 2 GeO 4 : Mn 2+ phosphors show green emission upon ultraviolet or near ultraviolet excitation. In optimized conditions, the products show a sub-microrod morphology with average size of about 200 nm. Under the excitation of 254 nm light, the Zn 2 GeO 4 : Mn 2+ nanophosphors exhibit bright green emission at peak wavelength of 535 nm.