A three-dimensionally interconnected molybdenum trioxide (MoO 3 )/polypyrrole (PPy)/reduced graphene oxide (rGO) composite was synthesized via an eco-friendly three-step method. The as-obtained electrode shows a high specific capacity of 412.3 F g –1 at a current density of 0.5 A g –1 and a good cycling stability (85.1% of the initial specific capacitance after 6000 cycles at 2 A g –1 is retained), and these excellent electrochemical performances can be attributed to the unique structure, remarkable electrical conductivity, and the synergetic effects between MoO 3 , PPy, and rGO. Furthermore, a symmetric supercapacitor based on a MoO 3 /PPy/rGO electrode was assembled to investigate the practical application performance of this material. The results demonstrate a high energy density of 19.8 W h kg –1 at a power density of 301 W kg –1 . These findings shine a light on the rational design of electrode materials with multicomponents for high-performance supercapacitors.

Doping of carbon-based materials with heteroatoms is an efficient method to increase their electrocatalytic activities. In the present study, a one-step solvothermal method to prepare nitrogen and sulfur co-doped graphene (NSG) using thiourea and graphene oxide (GO) as raw materials, has been reported. For supercapacitor applications, NSG exhibited higher capacitive properties compared to undoped graphene (UG). The as-fabricated material displayed superior gravimetric specific capacitance of 176.5 F/g at 1.0 A/g and also showed outstanding long-term cyclic stability (95.0% capacitive retention after 10000 cycles).

The development of supercapacitors with a high energy density and power density is of great importance for the promotion of energy storage technology. In this study, we designed and prepared petal-like CoMoO 4 clusters combined with carbon cloth as an excellent self-standing and binder-free electrode for asymmetric supercapacitors. Due to the abundant electrochemical active sites, the promising electron conduction, and ion diffusion rate, the CoMoO 4 @carbon cloth (CoMoO 4 @CC) electrode exhibits an excellent electrochemical performance. The results show that the CoMoO 4 @CC material exhibits a high specific capacitance (664 F/g at a current density of 1 A/g) and an excellent cycle stability (capacitance remains at 84.0% after 1000 cycles). The assembled symmetrical supercapacitor has an energy density of 27 Wh/kg when the power density is 600 W/kg. Even at a higher power density (6022 W/kg), it still maintains a good energy density (18.4 Wh/kg).

In this work, MoO2@NPGA nanocomposites were successfully prepared via a simple hydrothermal and calcination route.The as-prepared MoO2@NPGA composites exhibit a synergistic effect between MoO2 and N, P codoped graphene aerogels, which can significantly improve the electrochemical performance of the MoO2@NPGA electrodes. Moreover, the results also proved that the mass loading of MoO2 has a huge effect on the electrochemical properties of MoO2@NPGA composites. With an appropriate amount of MoO2, the MoO2@NPGA composite shows a high specific capacitance (335 F g-1 at 1 A g-1) and excellent cycle stability (capacitance remains at 88% after 6000 cycles). Futhermore, the assembled symmetric supercapacitor displays a high energy density of 23.75 W h kg-1 at a power density of 300 W kg-1 and can maintain an energy density of 17.1 W h kg−1 when the power density reaches up to 6005 W kg−1.

Uranium is the most basic ingredient for nuclear energy production, and its sources are mainly concentrated in mineral, as well as seawater and saline lake brine. Amidoxime-based functional adsorbents play an indispensable role in the efficient recovery of uranium from varied sources. However, it is empirically considered that for amidoxime adsorbents, balancing adsorption capacity and selectivity is challenging in the presence of complex interfering ions, especially for vanadium. Herein, a kind of amidoxime-modified mesoporous polymer microsphere with an optimized distance among functional groups was synthesized, which has remarkable chemical stability and ion selectivity. It is impressive that the adsorption capacity of the above-mentioned amidoxime microspheres for uranium in natural saline lake brine reached 15.9 mg/g, which was two orders of magnitude higher than that of vanadium. Combined with enhanced adsorption capacity, excellent selectivity, and ultra-high stability, amidoxime-functionalized mesoporous polymer microspheres emerge as a promising adsorbent for uranium extraction from natural saline lake brine.