Porphyrin Organic Framework Hollow Spheres and Their Applications in Lithium-Sulfur Batteries.

Organic frameworks represent an emerging family of advanced materials that can be precisely controlled at the atomic level. However, morphology control of organic frameworks remains perplexing and difficult, strongly limiting the advantages of organic frameworks in multiple practical applications. Herein, porphyrin organic framework hollow spheres (POF-HSs) are fabricated by a template method as a proof of concept of organic frameworks with precisely controlled morphology. POF-HS exhibits explicit chemical structures of 2D POF and an expected hollow structure. The morphology of POF-HS is further regulated in terms of void size and shell thickness. Benefited from the polar chemical structures and the hollow spherical morphology, POF-HS sufficiently mitigates the shuttle of polysulfides by taking the dual effects of chemical adsorption and physical confinement and functions as a desirable host material for sulfur cathode to endow lithium-sulfur batteries with high capacity, long cycling life, and excellent rate performance. The accurate synthesis of POF-HSs demonstrates the highly controllable and versatile morphology of organic framework materials beyond precise integration of organic building blocks and represents infinite possibility of offering exotic organic frameworks for chemistry, sustainable energy, and material science.