Shape Engineering of Biomass-Derived Nanoparticles from Hollow Spheres to Bowls through Solvent-Induced Buckling

Graphical Super Bowl C ! Non-centrosymmetric nanospheres are prepared by a soft-templating method using biomass as a precursor. Post-treatment of the nanospheres with different solvents can result in retention of the spherical structure or a shapeshift into nanobowls. The nanobowls are used as a support material for loading a CoS 2 catalyst and show excellent activity for the selective hydrogenation of aromatic nitro compounds. The realization of asymmetric hollow carbonaceous nanostructures remains a great challenge, especially when biomass is chosen as the carbon resource through hydrothermal carbonization (HTC). Herein, a simple and straightforward solvent-induced buckling strategy is demonstrated for the synthesis of asymmetric spherical and bowl-like carbonaceous nanomaterials. The formation of the bowl-like morphology was attributed to the buckling of the spherical shells induced by the dissolution of the oligomers. The bowl-like particles prepared through this solvent-driven approach demonstrated a well-controlled morphology and a uniform particle size of approximately 360 nm. The obtained nanospheres and nanobowls were loaded with CoS 2 nanoparticles to act as heterogeneous catalysts for the selective hydrogenation of aromatic nitro compounds. As expected, the CoS 2 /nanobowls catalyst showed good tolerance to a wide scope of reducible groups and afforded both high activity and selectivity in almost all the tested substrates.