It is necessary to efficient detection hydrazine in food . Exploring highly sensitive, low-cost and fast response electrochemical hydrazine sensing methods has been a challenge in this field. In this paper, a conformal transformation method is used to prepare rose flower-like NiCo-LDH derivating from the bimetallic NiCo-MOFs, and the N 2 H 4 sensing platform with a large electrocatalytic area, high conductivity and good stability was constructed. Based on the synergy between Ni and Co and the remarkable catalytic activity of the rough 3D flower-like structure, the N 2 H 4 sensor has a linear response in the concentration range of 0.001–1 mmol/L and 1–7 mmol/L, with a sensitivity of 5342 μA L mmol −1 cm −2 and 2965 μA L mmol −1 cm −2 (S/N = 3), respectively, and low limit of detection of 0.043 μmol/L. This study opens a new door for the successful application of electrochemical sensors to detect N 2 H 4 in real food samples.
Ju Zhang,Junli Wang,Xuanbing Wang,Naixuan Zong,Jinlong Wei,Jing Wang,Can Zhang,Yuantao Yang,Shengyou Su,Tianyang Liu,Ruidong Xu,Linjing Yang
Transition metal sulfides are widely recognized for their low cost, low toxicity, high safety, and potential as a positive electrode material for supercapacitors. However, due to its own volume effect, it usually has poor capacitance retention as positive electrode materials. Herein, the NiS/NiCo-LDH (Layered double hydroxide, LDH) electrodes with considerable practical application potential is designed and prepared. The composite electrodes are prepared by a simple two-step electrodeposition process. The NiS/NiCo-LDH electrode, with its rational design, exhibits more superior electrochemical performance compared to a single NiS electrode. The NiS/NiCo-LDH electrode shows a mass specific capacitance of 2620 F/g at a current density of 1 A/g, which is 1.88 times that of the single NiS electrode. Furthermore, the assembled NiS/NiCo-LDH//AC hybrid supercapacitor (HSC) device achieves an energy density of 93.3 Wh kg −1 at a power density of 800 W kg −1 . Therefore, this work provides a new strategy for preparing supercapacitor electrode materials with excellent electrochemical performance.
The suboptimal multifunctionality exhibited by structural supercapacitors (SSC) can be ascribed to a range of factors, encompassing the trade-off between electrical and mechanical performance of electrolyte, an inadequate interface contact between the electrode and electrolyte, as well as sluggish ion transport in the electrode and electrolyte. Herein, a new SSC architecture is introduced. First, the molybdate-ion-intercalated NiCo-LDH electrode is prepared by a convenient hydrothermal process. Benefiting from the unique 3D flower-like structure and MoO 4 2− doping effect, the as-prepared NiCo-LDH-MoO 4 2- -1 possesses high capacitance (1937.7 F g −1 ) and reversible charge-discharge stability. Subsequently, the PVA/PAA-cement composite is prepared by constructing a dual polymer-cement interwoven network. The rich intertwined network structure endows the composite with excellent mechanical and electrical properties, manifesting in a 189 % improvement in compressive strength and a 427 % augmentation in ionic conductivity compared to the pure cement. Meanwhile, an all-in-one SSC is assembled by an integrated polymerization-hydration synchronization strategy to improve interface contact. The resulting device presents superb energy density of 37.1 Wh kg −1 and long-life cycles. On the basis of these unique features, the device can be integrated into houses or road substrates for energy autarkic shelters and self-charging roads, which will significantly contribute to the development of new energy technologies and carbon neutrality fields.
危险品化学品经营许可证（带存储）