Covalent stabilization and functionalization of MXene via silylation reactions with improved surface properties

As an emerging 2D material, MXene combing hydrophilic surface, metallic conductivity and rich surface chemistry, has drawn much attention for applications ranging from electronic devices to electrochemical energy storage. However, the stability of MXene needs improvement, which is crucial to related applications. Here, we report a facile silylation reaction for efficient stabilizing the MXene against structural degradation due to spontaneous oxidation and improved surface properties with adjustable hydrophilicity. (3-Aminopropyl)triethoxysilane functioned MXene (APTES-MXene) was chosen as the model to evaluate the stability and surface property changes. By measuring the UV-Vis absorbance change of samples, the stability could be facilely monitored. The stability of the MXene in air degraded by 17.1%, 35.4%, 65.3% and 95.6% after 1, 3, 6 and 11 days, respectively. In contrast, the stability of APTES-MXene only reduced 20.8% after 11 days. Other silylating reagents were also explored and exhibited similar boosted stability with additional surface regulation from hydrophilic to hydrophobic.