Energy-efficient synthesis of Ti3C2Tx MXene for electromagnetic shielding

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Traditional methods for synthesizing two-dimensional Ti3C2Tx MXenes such as hydrofluoric acid (HF) or LiF/HCl based etching can be time-consuming, complex, and often result in low yields. They generally involve multi-step processes involving >40 h of preparation time that can expose the materials to harsh conditions. In this study, we demonstrate a rapid single-step microwave (MW) synthesis method that significantly reduces production time to 90 min, achieving a 90 % yield and cutting energy consumption by 75 %. For the first time, synchrotron x-ray pair distribution function (PDF) analysis conducted on MW-synthesized MXene (MW-Ti3C2Tx) indicates greater structural fidelity in local atomic ordering, indicating high-quality which is comparable to conventionally synthesized counterparts (CO-Ti3C2Tx). This method achieves similar or greater structural quality in less time while also enhancing electromagnetic interference shielding (EMI SE) performance. A 15 μm MW-Ti3C2Tx film demonstrated an impressive EMI SE of ∼67 dB in the X-band, compared to the ∼63 dB achieved by CO-Ti3C2Tx. The enhanced EMI SE performance is attributed to the presence of fluorine terminations, which provide oxidation resistance, increased conductivity and improved absorption of EM waves. The MW-induced shocks during irradiation not only help remove O2/OH groups, preventing oxidation, but also tunes the functional groups, enhancing charge transport and effective EM wave attenuation. The MW synthesis method presents a fast, efficient, and scalable approach for producing high-quality MXene nanosheets, paving the way for advancements in EMI shielding and other applications.