Hollow Metal–Organic Framework Microparticles Assembled via a Self-Templated Formation Mechanism

Hollow particles are considered to be fascinating materials due to their useful applications and unique properties. Understanding the formation mechanism of hollow structures is critical for their controlled formation. Herein, we demonstrate the fabrication of hollow metal–organic framework (hollow MOF) microparticles via a one-step solvothermal reaction of Zn­(NO₃)₂ and 1,3,5-benzenetricarboxylic acid (H₃BTC) without extra template materials. The formation mechanism study of the hollow MOF reveals a unique self-templated formation mechanism consisting of three stages: (1) spherical microparticles are initially formed during the early stage of the reaction, (2) the initially formed spherical microparticles act as self-templates for the growth of new crystalline MOF materials during the middle stage of the reaction, and (3) the initially formed spherical microparticles spontaneously disappear for the formation of hollow MOFs during the late stage of the reaction