Nickel cobaltite composite electrodes were fabricated by a fast, scalable, and cost-effective electrophoretic deposition for supercapacitor applications. NiCo 2 O 4 /PANI/rGO composite electrode went through heat treatment under nitrogen to carbonize PANI after electrophoretic deposition. NiCo 2 O 4 platelets, distributed on carbonized polyaniline−rGO network, were active in charge storage with high capacitance, excellent rate capability (1235 F g −1 at 60 A g −1 ), and acceptable cycling stability (3000 cycles at 10 A g −1 ) in a three-electrode assembly. The practical application of the composite electrode was investigated by an all-solid-state asymmetric supercapacitor cell using NiCo 2 O 4 /C-PANI/rGO as the cathode and activated carbon as the anode with specific capacitance of 262.5 F g −1 at 1 A g −1 and a good capacitance retention of 78% after 3500 cycles at an expanded working potential of 1.5 V. This work shows the importance of the composite assembly process that governs the microstructure of the composite.

Highly porous Co3O4/NiCo2O4 nanostructures were synthesized using zeolitic imidazolate framework-67 (ZIF-67) nanocrystals. The oxide composite structure was adjusted by modifying ZIF-67 crystallite size and the pore structure by the coordination modulation method. After forming the zeolite imidazolate framework-67 (ZIF-67)/Ni–Co layered double hydroxide intermediate composite through reaction with nickel nitrate, the intermediate composite was heated in air to result in Co3O4/NiCo2O4. Nitrogen adsorption was used for pore structure characterization of the template and resultant oxide composite. The maximum capacitance of nanostructured Co3O4/NiCo2O4 was 770 F g–1 at a discharge current density of 1 A g–1 with acceptable cycle stability, maintaining 70% of the initial capacitance after 10,000 charge–discharge cycles.

A reliable, simple, and sensitive fluorescence method was developed for the determination of methyl parathion (MP) in rice using MoS2 quantum dots (QDs).

No abstract

The impact of mechanical activation on calcium hydroxide-based sorbent was investigated. Carbonation/decarbonation kinetics and sorbent cycle stability were characterized by in situ X-ray diffraction. By increasing the speed of ball milling, we could reduce the particle size and crystallite size while increasing the pore volume in the sorbent as evidenced by XRD, dynamic light scattering, and nitrogen physisorption. At 700 °C, mechanically activated (500 rpm planetary ball milled) sorbent showed a 24% increase in capture capacity over 10 isothermal carbonation–regeneration cycles when compared to the sorbent without mechanical activation. The possible reason behind this improvement is discussed, which links the microstructure evolution and sorbent regeneration rate.