Tailoring Zn-based zeolitic imidazolate frameworks <i>via</i> Ni substitution: a strategy for enhanced selective alcohol adsorption and separation

A stable four-coordinated nickel node has been successfully incorporated into a Zn-based zeolitic imidazolate framework (ZIF-8) <i>via</i> a facile one-pot synthesis at room temperature. By tuning the Ni/Zn ratios, the resulting physicochemical properties have been verified. The incorporation of Ni has led to improved alcohol separation compared to the single metal structure. The Ni-substituted ZIF-8, denoted as ZnNi, demonstrates selective adsorption and separation of alcohol molecules based on size and molecular interaction, effectively capturing trace methanol from ethanol mixtures. The partial substitution of ZnN₄ with Ni introduces additional Ni centers and enhanced microporosity, which are potentially the key to such performance. These findings provide valuable insights into the development of mixed-metal organic frameworks for separation applications.