The fabrication of electrode materials with a high specific capacitance is essential for the development of enhanced performance supercapacitors. A novel binder-free electrode material, composed of MnS/Ni 3 S 2 and Co(OH) 2 , was synthesized on nickel foam by hydrothermal, sulfuration, and electrodeposition techniques. The MnS/Ni 3 S 2 exhibited a unique flower-like structure, resulting in a high specific capacitance of 1780 F g −1 at 1 A/g. By optimizing the synthesis conditions through several characterization and electrochemical tests, the MnS/Ni 3 S 2 @Co(OH) 2 composite was obtained, which displayed an ultrahigh specific capacitance of 2495 F g −1 at 1 A/g and a capacitance retention rate of 86.1% after 5000 cycles at 10 A/g in three-electrode system. The synergistic coupling of MnS/Ni 3 S 2 and Co(OH) 2 , along with the conductive nickel foam substrate, donated towards the excellent electrochemical performance. Furthermore, the MnS/Ni 3 S 2 @Co(OH) 2 //AC asymmetric supercapacitor (ASC) device was constructed with MnS/Ni 3 S 2 @Co(OH) 2 as positive electrode, activated carbon (AC) as negative electrode and 1 M KOH solution as electrolyte, demonstrated a high energy density of 68.6 Wh kg −1 at 750 W kg −1 and excellent cycle stability with 91.2% capacitance retention after 10,000 cycles at 15 A/g. The outstanding electrochemical properties observed in both the pre-electrodeposition and post-electrodeposition samples indicate the effectiveness of reasonable design and construction of composite as a pathway for producing electrode materials with exceptional performance.
Xiaoqian Ma,Han Zhang,Yi Zhao,Shuai Ma,Xiaoli Bai,Yuanchun Zhang,Daomei Chen,Jiaqiang Wang
Self-cycled photo-Fenton system, which integrates photocatalysis with Fenton technology, is investigated thoroughly in wastewater treatment due to the virtues of no addition of H 2 O 2 and accelerated circulation of Fe 2 + /Fe 3+ . Here we report an enhanced sulfur vacancy modified α-MnS/Ni 3 S 2 on nickel foam(NF), the simple hydrothermal successfully fabricated the magnetic floriform α-MnS/Ni 3 S 2-x /NF rich in sulfur defects. α-MnS enhanced the sulfur vacancy and further improved the hydrogen peroxide production performance of floriform Ni 3 S 2 . Without the external addition of both H 2 O 2 and Fenton-like metal ions, α-MnS/Ni 3 S 2-x /NF floriform exhibited an extremely high H 2 O 2 production rate of 51.6 mM·h −1 ·g −1 under visible light irradiation, which is the highest than those reported photocatalysis self-Fenton system in the literature. Interestingly, the self-cycled photo-Fenton strategy can be applied to the reduction of Cr(VI) and oxidative degradation of oxytetracycline hydrochloride(OTC), and the corresponding degradation and reduction rates all reach up to 98 %. The wide-spectrum light harvesting, photothermal effect and solar-driven photocatalysis in the α-MnS/Ni 3 S 2-x /NF are beneficial for the synergistically enhanced thermal-assisted photodegradation toward wastewater with a water evaporation rate of 2.01 kg·m −2 ·h −1 . Furthermore, a series of experiments and calculations were carried out to verify the photocatalytic mechanism. Density function theory (DFT) calculation shows that the formation of sulfur defects increases the number of active sites, decreases the energy barrier, and improves the activity and selectivity. In addition, α-MnS/Ni 3 S 2-x /NF floriform also exhibited good performance in real wastewater containing fluoronitrobenzene from a factory. Our findings may help the development of novel functional nanostructures for applications in environmental remediation and solar steam generation.
危险品化学品经营许可证（带存储）