Sized-controlled ZIF-8 nanoparticle synthesis from recycled mother liquors: Environmental impact assessment

The effect of different deprotonators as well as washing steps and drying procedure on the synthesis of ZIF-8 from the mother liquor was investigated. The morphology, thermal stability, crystallinity, and surface area of the synthesized MOF were investigated. In addition, life-cycle assessment (LCA) or, in other words, eco-balance, was implemented as well. LCA compares the full range of environmental effects associated with the product by evaluating all inputs and outputs of material flows and predicting how such flow will affect the environment. ZIF-8 nanocrystals were synthesized from the recycled mother liquors using NaOH or NH4OH thus preserving the main characteristics of the ZIF-8 nanoparticles derived from the initial synthesis. The rest of the characterization methods confirmed the suitability of the synthesis methodology considering the phase purity of the obtained ZIF-8 and nanometer size particles. This procedure enabled us not only to obtain phase pure ZIF-8 but also to substantially decrease the amount of solvent used for washing making it a sustainable process.This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 760944 (MEMBER project). Also, financial support from the Spanish Ministry of Science, Innovation and Universities and FEDER (MAT2016-77290-R), the Aragón Government (T43-17R) and the ESF is gratefully acknowledged.Peer reviewe