Facile Synthesis of Porous Mn₃O₄ Nano­crystal–Graphene Nanocomposites for Electrochemical Supercapacitors

Abstract

In this work, we describe our efforts to produce Mn3O4–graphene nanocomposites based on a convenient andfeasible solution based synthetic route under mild conditions. According to transmission electron microscopy (TEM) and high angle annular dark field scanning transmission electron microscopy (HAADF‐STEM) results porous Mn3O4 nanocrystals (NCs), 20–40 nm in size, are uniformly deposited on both sides of the graphene nanosheet (GNS) matrix. Significantly, the as‐prepared Mn3O4–graphene nanocomposites exhibit remarkable pseudocapacitive activity including high specific capacitance (236.7 F g–1 at 1 A g–1), good rate capability (133 F g–1 at 8 A g–1), and excellent cyclability (the specific capacitance only decreases by 6.32 % of the initial capacitance after 1000 cycles). The excellent pseudocapacitive performance of the Mn3O4–graphene nanocomposites electrode is probably due to the positive synergistic effects between the Mn3O4 and GNS. Namely, the intimate combination of the conductive graphene network with uniformly dispersed porous Mn3O4 NCs not only greatly improves the electrochemical utilization of Mn3O4, but also increases the double‐layer capacitance of the graphene sheets. These characteristics make this nanocomposite a very promising electrode material for high performance supercapacitors.

Strongly coupled graphene/Mn 3 O 4 composite with enhanced electrochemical performance for supercapacitor electrode

“…As shown in Fig. 3b, in the FT-IR spectrum of GO, the peaks around 3400 cm -1 , 1730 cm -1 , 1620 cm -1 , 1410 cm -1 and 1060 cm -1 are ascribe to the stretches of O-H, C=O, aromatic C=C, carboxyl C-O and alkoxy,respectively, in good agreement with previous report[34]. Compared with the spectrum of GO, the peaks of GM composite for oxygen containing function groups are dramatically weakened or entirely removed, indicating that reduction of GO and restoration of the conjugated aromatic system have occurred in the composite by an effective thermal treatment[35].…”

Tailoring the size and electrochemical performance of Mn3O4 nanoparticles by controlling the precipitation process

“…As shown in Fig. S1 and S2, the CV curves of the two samples at scan rates from 5 to 100 mV s -1 present typical rectangular shape similar to that of EDLCs within a much wider potential window (1.2 V) than that reported in other works (0.8-1 V) [15,[29][30][31][32][33][34]. The rectangular shape of CV curves indicates the linear dependence of the stored charge with the width of the potential window, suggesting the similar electrochemical behavior of Mn 3 O 4 nanoparticles to EDLCs [35].…”

Preparation of a hybrid core–shell structured BaTiO 3 @PEDOT nanocomposite and its applications in dielectric and electrode materials

“…Where, I is the response current density (A cm -1 ), V is the potential (V), v is the potential scan rate (mV s -1 ), and m is the mass of the BaTiO 3 @PEDOT composites in the electrode (g) [33]. Fig.6 (A) shows the CV curves of BaTiO 3 @PEDOT-4 composites at different scan rate, and other CV curves of BaTiO 3 @PEDOT can be seen in Fig.…”