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Rational design of micro-nano morphology and suitable crystalline structure are highly desired for metal hydroxides to achieve overall high-performance in the advanced electrodes for flexible supercapacitors. Herein, a novel wisteria flower-like microstructure of cobalt-nickel double hydroxide (CoNi-DH) is successfully constructed on carbon cloth (CC) using an in-situ hydrolysis-induced exchange process between hydroxide ions and organic ligands of the Co-MOF in four different kinds of solutions containing Ni2+. The as-prepared wisteria flower-like microstructure grown on CC shows vertically aligned arrays with high specific area and abundant active sites, which not only guarantee the CoNi-DH active materials to be thoroughly exposed in the electrolyte, resulting in highly effective pseudocapacitive energy storage, but also are beneficial to rapid and reversible redox kinetics and thus give rise to high-rate capability. In addition, compared to Ni(NO3)2, NiCl2, and Ni(CH3COO)2 solutions, the Ni2SO4 solution is found to facilitate the formation of the most regular morphology and the largest interlayer spacing on (003) plane of the layered nickel hydroxide phase in the resultant CoNi-DH. As a result, the optimal CoNi-DH-S@CC (CoNi-DH prepared in Ni2SO4) serves as an advanced electrode to show high-rate capability (only 13% Cs decay after a 15-fold current elevation) and a superior specific capacity (Cs) of 929.4 C g-1, which remarkably exceeds those of CoNi-DH-N (823.1 C g-1, in Ni(NO3)2), CoNi-DH-Cl (798.4 C g-1, in NiCl2), CoNi-DH-C (803.8 C g-1, in Ni(CH3COO)2), and other similar metal hydroxides. Moreover, with this CoNi-DH-S electrode as the positive electrode, the as-prepared asymmetric supercapacitor (ASC) delivers an impressive capacity of 204.8 C g-1, a superior energy density of 42.5 Wh kg-1, and satisfactory cycle life (81.5% reservation after 7500 cycles). As a proof-of-concept application, a quasi-solid-state ASC is further successfully fabricated based on the CoNi-DH-S electrode to exhibit encouraging application potential.

Low-cost, high-performance, and long-life cathode materials are highly desired for zinc ion hybrid supercapacitors (ZHSs). Here, an N, O co-doped two-dimensional (2D) carbon nanosheet material is successfully fabricated via a one-step combustion conversion of wood for the excellent usage as the cathode material in zinc-ion hybrid supercapacitors. This novel combustion conversion synthesis with Zn(NO3)2·6H2O as oxidizer and urea as fuel can easily achieve the carbonization, pore-forming, and heteroatom doping within a one-step process. More interestingly, the resulting N, O co-doped porous carbon owns relatively uniform 2D sheet structure and very high specific surface area (1248 m2 g−1), which can not only provide short electric/ionic transfer path plus optimized wettability and conductivity for high power output, but also offer abundant interfacial active sites as well as improved ion adsorption capacity for high energy storage. Benefiting from these advantages, the ZHS based on this N, O co-doped 2D carbon nanosheets exhibits a superior specific capacity of 111.0 mAh g−1 at 0.1 A g−1, high rate capability of 57.6% capacity retention at a 30-fold higher current, and attractive energy density of 109.5 Wh kg−1 at 225 W kg−1. More gratifyingly, it displays ultralong cycling life with 92.7% capacity reservation after 50,000 charge and discharge cycles. Moreover, a quasi-solid ZHS with N, O co-doped 2D carbon nanosheets coated on the carbon cloth as the cathode also displays satisfactory specific capacity (34.6 mAh g−1), impressive energy density (27.7 Wh kg−1), and nice flexibility.

Perylene-3,4,9,10-tetracarboxylic acid (PTCA) was found to form stable Langmuir films at the air/water interface through the coordination with Cu(II) ion in the subphase although the compound itself could not form monolayer on a plain water surface. The Langmuir films can be transferred onto solid substrates by a Langmuir–Schaefer (LS) method. Surface pressure–area isotherm and measurement of the UV–Vis and FT-IR spectra of the transferred LS films confirmed the coordination between the carboxylic group and Cu(II) ion in the Langmuir films. Atomic force microscopy (AFM) measurements indicated that the Langmuir film was composed of small nanoparticles with a diameter of several tens of nanometers. X-ray diffraction (XRD) measurement on the transferred LS films revealed that the film formed a clear layer structure with a distance of 3.9 nm, which was in agreement with the height measurement from the AFM.

As part of our studies on green agrochemical formulations, four o/w agrochemical microemulsions have been prepared using five non-ionic surfactants with various hydrophilities and one co-surfactant. The effects of various formulation conditions, including surfactants, surfactant concentration, mixture of surfactant with various concentrations, pesticides in oil phase and water quality in the continuous medium on the cloud points of microemulsions have been investigated. The results showed that the values of the cloud point of microemulsions were depended on the nature of agrochemical, the surfactants used and the concentration of surfactants. Surfactants with higher HLB value at same concentration produce more stable agrochemical microemulsions, i.e. with higher cloud point. The results showed that the match between surfactant and oil phase or pesticide oil phase was the key to formulate stable microemulsions. However, the water quality was showed almost no effect on the cloud point of the agrochemical microemulsions in the studies.