Generalized assembly of sandwich-like 0D/2D/0D heterostructures with highly exposed surfaces toward superior electrochemical performances
Shuqing Xue, Guanhong Wu, Mingzhong Li, Zihan Liu, Yuwei Deng, Wenqian Han, Xuanyu Lv, Siyu Wan, Xiangyun Xi, Dong Yang, Angang Dong
Abstract
Heterostructures composed of two-dimensional (2D) nanosheets and zero-dimensional (0D) nanoparticles (NPs) have attracted increasing attention because of the synergy arising from the coupling interactions between the two mixed-dimensional components. Despite recent advances, it remains a challenge to fabricate 2D/0D heterostructures with clean and accessible surfaces, which is highly desirable for the diversity of catalytic, sensing, and energy storage applications. Herein, we report a generalized methodology that enables the facile assembly of sandwich-like 0D/2D/0D heterostructures with facilitated mass-transport channels and exposed surface active sites. A ligand-exchange strategy with HBF4 is employed to strip off the surface-coating ligands of colloidal NPs, rendering them positively charged and dispersible in polar solvents. This allows subsequent electrostatic assembly of NPs with oppositely charged 2D nanosheets to afford sandwich-like 0D/2D/0D heterostructures. The barely covered surfaces and the advantageous architectures of such sandwich-like 0D/2D/0D heterostructures induce the desired synergistic effect, making them particularly suitable for electrochemical energy storage and conversion. We demonstrate this by employing MXene/NiFe2O4 and MXene/Fe3O4 heterostructures for high-performance electrocatalytic oxygen evolution and supercapacitors, respectively.