Metal nano-drills directionally regulate pore structure in carbon

Abstract

The exact control of pore structure in carbon is desirable for offering a leap forward in a wide range of industrial applications, but the intractable hurdle relating to the anisotropic etching of carbon remains. Here, metal nano-drills are developed by which controllable pore size and adjustable hole depth can be rationally designed in both SP2- and SP2-SP3 hybridized carbon. A new catalytic drilling behavior is demonstrated, whereby the catalytic metal nanoparticles (Ru, Ni, Au, Pt, etc.) as drilling forces, accompanied by chemical etching, thermodynamically catalyze the decomposition of the surface barrier layer (K2CO3) and dynamically accelerate the anisotropic carbon etching rates. Subsequently, metal nano-drills open the enclosed internal spaces of activation carbonized microtubes (RCMT). Benefiting from the drilling structure featured by outer-inter connecting, RCMT exhibits 2.5 times higher Li2O2 accommodation capacity as the lithium-oxygen battery cathode and 2.8 times higher specific capacitance as the electric double-layer supercapacitor electrode than the carbonized microtube without the drilling process.