Advanced Structures & Composites Center

Published: 2023

Publication Name: Advanced Materials

Publication URL: https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.202300422

Abstract:

MXenes, 2D transition metal carbides, nitrides, and carbonitrides, have been
investigated for diverse applications since their discovery; however, their
life-cycle assessment (LCA) has not been studied. Here, a “cradle to gate” LCA
is performed to assess the cumulative energy demand (CED) and
environmental impacts of lab-scale synthesis of Ti3C2Tx, the most researched
MXene composition. Electromagnetic interface (EMI) shielding is selected as
it is one of MXenes’ most promising applications and LCA of Ti3C2Tx
synthesis is compared to aluminum and copper foils, two typical
EMI-shielding materials. Two laboratory-scale MXene synthesis
systems—gram and kilogram batches—are examined. The CED and
environmental implications of Ti3C2Tx synthesis are investigated based on its
precursor production, selective etching, delamination processes, laboratory
location, energy mix, and raw material type. These results show that
laboratory electricity usage for the synthesis processes accounts for >70% of
the environmental impacts. Manufacturing 1.0 kg of industrial-scale
aluminum and copper foil releases 23.0 kg and 8.75 kg of CO2, respectively,
while 1.0 kg of lab-scale MXene synthesis releases 428.10 kg. Chemical usage
is less impactful than electricity, which suggests that recycled resources and
renewable energy can make MXene synthesis more sustainable.
Understanding MXene LCA helps the industrialization of this material.