Stabilizing Ti₃C₂T_x in a Water Medium under Multiple Environmental Conditions by Scavenging Oxidative Free Radicals

MXene nanosheets have been worthy contenders for various applications owing to their unique physicochemical properties but can be easily oxidized to lose their functional properties, especially in a water medium with unclear oxidation mechanism. Here, we investigate the effect of main free radicals in water on the oxidation of Ti3C2Tx and screen out the corresponding effective scavengers. It is found that ·OH is more detrimental to Ti3C2Tx in water, and agents such as NaHCO3 stabilizing Ti3C2Tx by scavenging ·OH have been proved to be effective at 50 °C and under visible light irradiation, extending the storage life of Ti3C2Tx colloids up to 140 days at 5 °C. As a proof of concept, the NaHCO3-stablized Ti3C2Tx is superior to the unprotected counterpart for supercapacitors and photocatalytic applications. It is expected that this study provides important insights into enhancing the oxidation resistance of Ti3C2Tx in water and facilitates the application of Ti3C2Tx-based materials under multiple environmental conditions.