2D Mesoporous Carbon with Hollow Turtle Shell-Like Morphology for Resolving Restacking Effect

In this work, a unique 2D hollow turtle shell-like mesoporous carbon (HTMC) synthesized via a ternary heterostructuring strategy to alleviate the restacking tendency of 2D materials is presented. The ternary 2D heterostructuring is achieved via an in situ growth of zeolitic imidazolate framework-8 (ZIF-8) on graphene oxide (GO) and a subsequent mesostructured polydopamine (mPDA) coating to obtain ternary heterostructured GO@ZIF-8@mPDA, which is then converted to the hierarchically porous HTMC having macro-, meso-, and micropores via direct carbonization. Additionally, 2D turtle shell-like microporous carbon (TMC) and 2D mesoporous carbon (MPC) derived from binary heterostructured GO@ZIF-8 and GO@mPDA, respectively, are synthesized to investigate the porosity effect on alleviating the loss of accessible surface area of restacked 2D carbons. Among them, HTMC demonstrates superior structural advantages for alleviating the negative effects of restacking in 2D materials, exhibiting by far the highest specific capacitance (C_sp) across all scan rates (93.7 F g^-1 at 500 mV s^-1 to 334.47 F g^-1 at 1 mV s^-1) in 1 M H₂SO₄. Furthermore, HTMC demonstrates outstanding rate capability while maintaining the greatest charge storage capacity over all scan rates.