Hexagonal WO₃ with well-ordered mesopores was achieved using a one-pot hydrothermal method, and it exhibited excellent capacitive performance.

Carbon aerogel (CA) microspheres were pyrolyzed from resorcinol–formaldehyde (RF) organic aerogels, which were prepared by emulsion polymerization of resorcinol and formaldehyde using ambient drying technique. Structural and microstructural characteristics of CA microspheres were investigated by scanning electron microscopy (SEM), Raman spectroscopic techniques and nitrogen adsorption. The SEM images show that the resultant CA microspheres are all fine spherical without cracks. Results of Raman spectroscopy indicate that CA microspheres are mainly formed by amorphous carbon structure with a few graphite carbons. The surface area and porosity analysis prove that the CA microspheres have high specific surface area (910 m² g⁻¹), appropriate pore size distribution (PSD) (3–15 nm) and high ratio of mesoporosity (44%). The results of cyclic voltammetry indicate that the CA microspheres have ideal capacitive behavior, and the maximum specific capacitance values of 83 F g⁻¹ was measured at a scan rate of 10 mV s⁻¹ in 1 M NaCl. These parameters can significantly improve the desalination capacity for the carbon-based electrode materials in capacitive deionization (CDI). The performance of CDI is investigated by different solution concentrations (500–650 mg L⁻¹) and applied voltages (0.8–1.4 V). With the optimum initial NaCl concentration of 500 mg L⁻¹ and applied voltage of 1.2 V, the specific salt-adsorption capacity for CA microspheres was found to be 5.62 mg g⁻¹. The electrosorption and electrodesorption procedures displayed the stability and regeneration of CA microsphere electrodes. This preliminary study demonstrated that the CA microsphere electrodes in CDI process can be considered to be an alternative candidate for desalination.

Recently, “Water-in-salt” electrolyte has been reported to extend the working voltage of aqueous supercapacitor. However, this electrolyte needs the electrode materials possess some good features such as proper pore structure, high electron and ion conductivity. Herein, we fabricated the nitrogen-doped multi-scale porous carbon (NMC) by the simple enriching melamine-resorcinol-formaldehyde xerogels method with integrating triblock copolymer for micro-pores formation. All the results confirmed that our NMC is provided with a very high specific surface area (3,170 m² g⁻¹) and its monoliths are composed of multi-scale porous structure. By employing the nanostructured NMC as electrode materials, we have investigated the capability for high-voltage aqueous supercapacitor applications. The superconcentrated “Water-in-salt” electrolyte expand stability operating potential window of aqueous symmetric supercapacitor up to 2.4 V with a high energy density of 33 Wh kg⁻¹ at power density of 0.3 kW kg⁻¹. Our studies indicate that the NMC is potential materials for high performance over wider voltage range.