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

: 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 CoS2 nanoparticles to act as heterogeneous catalysts for the selective hydrogenation of aromatic nitro compounds. As expected, the CoS2 /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.