Generation of color-controllable room-temperature phosphorescence via luminescent center engineering and in-situ immobilization

Materials with controllable luminescence colors are highly desirable for numerous promising applications, however, the preparation of such materials, particularly with color-controllable room-temperature phosphorescence (RTP), remains a formidable challenge. In this work, we reported on a facile strategy to prepare color-controllable RTP materials via the pyrolysis of a mixture containing 1-(2-hydroxyethyl)urea (H-urea) and boric acid (BA). By controlling the pyrolysis temperatures, the as-prepared materials exhibited ultralong RTP with emission colors ranging from cyan, green, to yellow. Further studies revealed that multiple luminescent centers formed from H-urea, which were in-situ embedded in the B 2 O 3 matrix (produced from BA) during the pyrolysis process. The contents of the different luminescent centers could be regulated by the pyrolysis temperatures, resulting in color-tunable RTP. Significantly, the luminescent center engineering and in-situ immobilization strategy not only provided a facile method for conveniently preparing color-controllable RTP materials, but also endowed the materials prepared at relatively lower temperatures with color-changeable RTP features under thermal stimulus. Considering their unique properties, the potential applications of the as-obtained materials for advanced anti-counterfeiting and information encryption were preliminarily demonstrated. (c) 2023 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Automated summary

A facile strategy was developed to prepare color-controllable room-temperature phosphorescence (RTP) materials through the pyrolysis of a mixture containing 1-(2-hydroxyethyl)urea and boric acid. By controlling the pyrolysis temperatures, the resulting materials exhibited ultralong RTP with tunable emission colors. The study also revealed the formation of multiple luminescent centers, in-situ embedded in the B2O3 matrix, by the pyrolysis process, allowing for color-tunable RTP.