Guanidinium-Based Polymerizable Surfactant as a Multifunctional Molecule for Controlled Synthesis of Nanostructured Materials with Tunable Morphologies.

Rationally and efficiently controlling the morphology of nanomaterials plays a crucial role in significantly enhancing their functional properties and expending their applications. In this work, a strategy for controlled synthesis of diverse nanostructured materials with tunable morphologies was developed using a guanidinium-based surfactant with a polymerizable pyrrole unit as a multifunctional molecule that can serve not only as a structure-directing agent for mesostucture formation but also as a monomer and carbon source. The unique self-assembly behavior of the guanidinium head group under different conditions allows the synthesized surfactants to form different aggregates and thus to produce silica nanomaterials with multiple morphologies (such as sphere, disk, fiber, and cocoon) in conjunction with sol-gel chemistry. Besides the mesostructured silicates, by further exploring the polymerization and carbonization features of pyrrole units that were densely packed in the formed silica nanochannels, diverse nanostructured materials such as mesostructured conducting polymers, carbon materials, and metal-nanoparticle (NP)-decorated forms could also be easily obtained in one-pot fashion for various applications, such as energy storage and catalysis. As a demonstration, carbon nanotubes and Pd-NP-doped hollow carbon spheres were fabricated, which exhibited good specific capacitance (101.7 F g-1) at the scan rates of 5 mV s-1 and excellent catalytic performance (100% conversion for three cycles) in the Suzuki C-C coupling reaction, respectively. All of the results indicate that our strategy may open a new avenue for efficiently accessing diverse nanostructured materials with tunable morphologies for wide applications.