Construction of Complex CoS Hollow Structures with Enhanced Electrochemical Properties for Hybrid Supercapacitors

Abstract

Hierarchical hollow nanostructures with complex shell structures are attractive for efficient storage of electrochemical energy. However, reports on the designed formation of such delicate architectures are rare. Starting from a framework of Co-based zeolitic imidazolate (ZIF-67) nanocubes, we demonstrate a templateengaged formation of double-shelled hollow structures with CoS-nanoparticleassembled nanoboxes surrounded by outer CoS-nanosheet-constructed shells (denoted as CoS-NP/CoS-NS DSNBs). Delicate manipulation of the templateengaged reaction between ZIF-67 and water leads to the formation of ZIF-67/ Co(OH) 2 -nanosheet yolk-shelled structures, which are then transformed into CoS-NP/CoS-NS DSNBs through the reactions with Na 2 S. As a result of the unique assembly of subunits with different dimensionalities, the CoS-NP/CoS-NS DSNBs have a high specific surface area, suitable mesopores, and good structural robustness, which contribute to exceptional performance as a battery-type electrode. Moreover, a hybrid supercapacitor is fabricated by using CoS-NP/CoS-NS DSNBs as the positive electrode and activated carbon as the negative electrode. Impressively, these optimized devices can be operated stably in a wide potential range of 1.6 V with greatly enhanced energy density and power capability. The device is stable for 10,000 cycles with a capacitance retention of 88%.

Metal–Organic‐Framework‐Derived Co3S4 Hollow Nanoboxes for the Selective Reduction of Nitroarenes

“…Firstly,z eolitic imidazolate framework (ZIF-67) nanocubes were prepared with cobalt nitrate hexahydrate and 2-methylimidazole as the precursors in the presence of hexadecyltrimethylammonium bromide (CTAB) surfactant, whichw as used as ac apping agent. [12] In the second, sulfurization step, thioacetamide was chosen as the sulfur source. In the final step, as imple thermal treatment resulted in the formationo fC o 3 S 4 / CN hollow nanoboxes.…”

“…Moreover,c hloro-,b romo-, and iodosubstituted substrates gave the desired anilines with excellent activity and selectivity and without any dehalogenated products detected by GC-MS. [26] Moreover, substrates containing thioether,c yano, quinolineN ,o ra mino groups are known to coordinate to Pd-based catalysts and poison them; [27] however,w ith the Co 3 S 4 /CN catalyst, all targeted anilines were obtained with excellent selectivities( Ta ble 2, entries [11][12][13][14][15]17). Furthermore, in the case of 1nitro-3-vinylbenzene, which has ah ighly active alkene carboncarbon double bond, only the nitro group was reduced and the vinyl group remained untouched (Table 2, entry 10).…”

“…[12] In at ypical experiment, Co(NO 3 ) 2 ·6H 2 O( 580 mg) and hexadecyltrimethylammonium bromide (CTAB, 30 mg) were dissolved into water (20 mL) to obtain ac lear solution. [12] In at ypical experiment, Co(NO 3 ) 2 ·6H 2 O( 580 mg) and hexadecyltrimethylammonium bromide (CTAB, 30 mg) were dissolved into water (20 mL) to obtain ac lear solution.…”

Synthesis of NiMoS4for High-Performance Hybrid Supercapacitors

“…10 On the basis of these circumstances, it is supposed that developing hybrid supercapacitors (HSCs) could be a promising approach to fulfill the high energy density without sacrificing the power density and cycle life. 11 HSCs are usually composed of one battery-type electrode and one capacitive electrode, which could combine advantages of batteries and supercapacitors, delivering enhanced capacitance and high energy density.…”

Co9S8nanoparticle-decorated carbon nanofibers as high-performance supercapacitor electrodes

“…Among the various metal suldes, Co 9 S 8 has proved itself as a promising material for supercapacitor electrode applications due to its high theoretical capacitance. [11][12][13] Different types of cobalt sulde nanostructures have been explored as supercapacitor electrodes, including nanospheres, 14,15 nanocages, 16 nanoowers, [17][18][19] and so on.…”