Preparation of Hierarchical MnCo₂S₄ Nanotubes for High‐Performance Supercapacitors and Non‐Enzymatic Glucose Sensors

Abstract

Hierarchical MnCo2S4 nanotubes have been successfully prepared via a facile self‐template approach. The as‐prepared hierarchical MnCo2S4 nanotubes are evaluated as electrode materials for supercapacitors, which exhibits a specific capacitance of 705.2 F g−1 at 0.5 A g−1 and a remarkable cycling performance. Moreover, the hierarchical MnCo2S4 nanotubes are also applied in non‐enzymatic glucose sensors, which possesses good electrocatalytic performances with a low determination limit (0.1 μM) and good selectivity. In addition, yolk‐shelled MnCo2O4 prisms were also prepared via the self‐template method. The electrochemical performance of the yolk‐shelled MnCo2O4 prisms were also studied. It is found that the as‐prepared hierarchical MnCo2S4 nanotubes show better electrochemical performances than yolk‐shelled MnCo2O4 in this work.

Solvothermal Synthesis of Mesoporous 3D‐CuCo2O4 Hollow Tubes as Efficient Electrocatalysts for Methanol Electro‐Oxidation

“…The catalytic activity of bare Ni foam was also tested to reveal its negligible current density in comparison with other electrodes towards methanol oxidation (Figure ). As shown in Figure a and Figure S11a, the area under the CV curves of monometallic CuO and Co 3 O 4 electrodes are smaller than the CuCo 2 O 4 samples reacted for 3, 4 and 5 h. Higher area under the curve of all the CuCo 2 O 4 electrodes indicates a higher electrochemical activity than that of CuO and Co 3 O 4 electrodes . Also, as illustrated in Figure a, CuCo‐4 has the largest enclosed area, which confirms that it has the highest electrochemical activity among the other CuCo 2 O 4 electrodes.…”

“…Also, as illustrated in Figure a, CuCo‐4 has the largest enclosed area, which confirms that it has the highest electrochemical activity among the other CuCo 2 O 4 electrodes. Furthermore, the reduction and oxidation peaks present in the working electrode correspond to the faradic redox reaction involving Cu 2+ /Cu + and Co 3+ /Co 2+ paired with OH − ions …”

“…The increased current density of CuCo‐4 electrode is almost 3.5‐fold higher than that of CuO and 2‐fold higher than Co 3 O 4 , which is mainly attributed to the co‐existence of Co and Cu elements. The addition of Cu ion improves the overall characteristic of the CuCo‐4 electrode in terms of surface area, porosity, ion‐electron transport, and electrochemical activity . Besides current density, the onset potential is another key factor in determining the performance of electrocatalysts in methanol oxidation .…”

Anchoring Spinel MnCo2S4 on Carbon Nanotubes as Efficient Counter Electrodes for Quantum Dot Sensitized Solar Cells

“…The O 1s peak arises from the surface oxidation of MnCo 2 S 4 /CNTs due to exposure to air. ,, By using the Gaussian–Lorentz mix fitting method, two spin–orbit doublets and one shake-up satellite (denoted as “Sat.”) can be observed in Figure b. The peaks located at 641.7 and 653.4 eV are assigned to Mn 2+ , and peaks at 643.7 and 654.5 eV are ascribed to Mn 3+ . ,, Similarly, the Co 2p spectrum is better fitted into two spin–orbit doublets (Co 2+ and Co 3+ ) and two shake-up satellites, , as shown in Figure c. In the high-resolution S 2p energy spectrum (Figure d), the peaks at 161.5 and 162.7 eV are associated with S 2p 3/2 and S 2p 1/2 , which are the typical metal–sulfur bond in the ternary metal sulfide.…”

Achieving Rich Mixed-Valence Polysulfide/Carbon Nanotube Films toward Ultrahigh Volume Energy Density and Largely Deformable Pseudocapacitors

“…The diffraction peak shift should be attributed to the difference in the crystal structure originated from varying Mn/Co/S atomic ratio. On the basis of the peaks, the lattice cell parameter of Mn x Co y S z compounds is calculated to be 9.723 Å, larger than that for MnCo 2 S 4 ( a = 9.407 Å from XRD peaks in ref ). This combined with HRTEM indicates that the lattice cell parameter and unit cell volume slightly increase with the Co/S ratio.…”