Sustainable manufacturing of CALF-20 via a ZnO-based route eliminating the washing step

Abstract

In this study, we present a sustainable and scalable synthesis route for CALF-20 by employing zinc oxide (ZnO) as the zinc source, thereby eliminating the washing step that is required in previously reported methods. CALF-20 synthesized using ZnO exhibits CO₂ adsorption performance comparable to the literature while achieving complete crystallization within 3 h and reaching a high zinc-based yield of 97.1%. This environmentally benign process significantly reduces liquid waste generation and simplifies post-synthetic purification, offering strong potential for cost-effective, industrial-scale MOF production.