Formation of covalent Ga–C bonds on liquid metal nanoparticles with enhanced stability and anti-oxidation

Surface modification of Eutectic Gallium Indium (EGaIn) to inhibit oxidation has been a long-term challenge in materials science, with limited research reporting the formation of a covalent bond between Ga and modifiers for stability purposes. Taking advantage of the strong reductive properties of EGaIn, this study developed a simple method for spontaneous reduction of aryldiazonium salts on the EGaIn nanoparticle surface to form stable covalent Ga-C sigma bonds, effectively suppressing surface oxidation. Comprehensive characterization confirmed the formation of the covalent Ga-C bond rather than Ga-NN-C bonds on the EGaIn nanoparticle surface. Approximately 20% of Ga(0) in EGaIn forms Ga-C bonds. Notably, the short chain aryl modified EGaIn nanoparticles exhibited high stability and negligible surface oxidation. This straightforward strategy for preparing stable aryl modified EGaIn nanoparticles allows the introduction of a range of ligands on the EGaIn nanoparticle surface, offering promising opportunities for diverse applications across multiple fields.