RESUMO
Recently, supercapacitors (SCs) are extensively explored as effective energy storage devices. Specifically, asymmetric SCs are being developed to enhance energy density using suitable materials with favorable nanostructures. This study describes the construction of a bismuth copper selenite (BCS-200) working electrode with an ultrathin nanosheet (UTNS) architecture. This morphology is achieved using a low-cost electrodeposition (ED) method, followed by annealing. The impact of ED time on the development of morphology is studied by synthesizing comparative electrodes simultaneously. The optimized BCS-200 electrode prepared with a deposition time of 200 s shows higher specific capacity/capacitance (Cs/Csc) values of 330.9 mAh g-1/2206.6 F g-1 than the other synthesized electrodes (BCS-100, BCS-150, BCS-250, and BCS-300). Besides, a vapor-grown carbon fiber (VGCF)-added Fe2O3 composite coated on nickel foam (NF) is developed as a negative electrode. The VGCFs@Fe2O3/NF electrode exhibits the (Cs/Csc) values of 183.5 mAh g-1/734.4 F g-1, which is associated with ultra-high cycling stability. In addition, the fabricated BCS-200 and VGCFs@Fe2O3/NF electrodes are combined to construct a wearable semi-solid-state asymmetric SC (SSASC) with an energy density (Ed) of 20.5 Wh kg-1 and a cycling stability of 91.7% over 40000 charge/discharge cycles. Furthermore, the real-time applicability of the SSASC is verified by powering it in practical applications.
RESUMO
Rational architecture design of the artificial protective layer on the zinc (Zn) anode surface is a promising strategy to achieve uniform Zn deposition and inhibit the uncontrolled growth of Zn dendrites. Herein, a red phosphorous-derived artificial protective layer combined with a conductive N-doped carbon framework is designed to achieve dendrite-free Zn deposition. The Zn-phosphorus (ZnP) solid solution alloy artificial protective layer is formed during Zn plating. Meanwhile, the dynamic evolution mechanism of the ZnP on the Zn anode is successfully revealed. The concentration gradient of the electrolyte on the electrode surface can be redistributed by this protective layer, thereby achieving a uniform Zn-ion flux. The fabricated Zn symmetrical battery delivers a dendrite-free plating/stripping for 1100 h at the current density of 2.0 mA cm-2 . Furthermore, aqueous Zn//MnO2 full cell exhibits a reversible capacity of 200 mAh g-1 after 350 cycles at 1.0 A g-1 . This study suggests an effective solution for the suppression of Zn dendrites in Zn metal batteries, which is expected to provide a deep insight into the design of high-performance rechargeable aqueous Zn-ion batteries.
RESUMO
It is crucial to develop an environmentally friendly and low-cost method to treat industrial effluent that contains soluble dyes and microbes. Most of the photocatalysts have been studied using an external light source that increases the cost of the purification process of effluent. This study focuses on developing efficient solar photocatalytic nanofoams. The controlled growth of ZnO nanofoams (CNZ nanofoams) in a simple method of thermal oxidation using a soft template is reported. Prepared nanofoams are characterized using X-ray diffraction, scanning electon microscopy and synchrotron soft X-ray absorption spectroscopy. By photocatalysis studies under direct sunlight it was found that within 120â min CNZ nanofoams degraded 99% of the dye. In addition, antimicrobial studies of multi-drug-resistant E.â Fergusonii isolated from wastewater was carried out. These antimicrobial results showed a good inhibition zone, indicating that prepared nanofoams are both an effective solar photocatalyst and an antimicrobial agent.