A high‐performance hybrid supercapacitor electrode based on ZnO/nitrogen‐doped carbon nanohybrid

Abstract

Abstract Hybrid nanomaterials offer promising properties to serve as an electrode for hybrid supercapacitors. Herein, dye (rhodamine B, RhB) encapsulated zeolitic imidazolate frameworks (RhB@ZIF‐8) was synthesized at room temperature via triethylamine (TEA)‐assisted method. The material was used as a precursor for synthesizing zinc oxide embedded nitrogen‐doped carbon (ZnO@N‐doped C) via the carbonization at different temperatures (400°C, 600°C, and 800°C). The materials were characterized using X‐ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal analysis (DTA), high‐resolution transmission electron microscope (HR‐TEM), energy‐dispersive X‐ray mapping (EDX), nitrogen adsorption–desorption isotherm, and X‐ray photoelectron microscope (XPS). ZnO@N‐doped C nanocrystals (15–20 nm) were used as an electrode for a hybrid supercapacitor. ZnO@N‐doped C exhibited a high capacitance of 1200 F·g −1 at a current density of 1 A·g −1 without losing any capacitance (87.7% of initial capacitance) even after 1000 galvanostatic charge–discharge cycles (GCDCs). The presence of a guest molecule such as RhB improved the capacitance of the carbonized ZIF‐8 two‐fold compared with the carbonized materials using conventional ZIF‐8.