Efficient removal of broad-spectrum organic pollutants is crucial in wastewater treatment. This research focuses on the synthesis of three-dimensional TiVCTX MXene/graphene nanosheet-based aerogels, known as TiVCTX/GAs, using a straightforward hydrothermal self-assembly method, followed by freeze-drying. The integration of bimetallic MXene and graphene aerogel in TiVCTX/GAs results in an impressive broad-spectrum removal capability for multiple organic contaminants from wastewater. TiVCTX/GAs exhibit effective adsorption of various dyes and drugs, with adsorption capacities reaching 319.67, 303.45, 229.97, 217.87, and 283.38 mg·g–1 for methylene blue, rhodamine B, Congo red, methyl orange, and tetracycline hydrochloride, respectively. To fully comprehend the adsorption mechanism of TiVCTX/GAs, various models for the adsorption process were examined including kinetic, isothermal, and thermodynamic models. The adsorption process aligns with the Langmuir model and the pseudo-second-order kinetic model. The intraparticle diffusion model suggests that intraparticle diffusion is not the only rate-controlling step. Moreover, thermodynamic analysis indicates that the adsorption process by TiVCTX/GAs is spontaneous. These aerogels also effectively remove common oils and organic solvents from wastewater through absorption treatment with a substantial absorption capacity ranging from 40 to 90 g·g–1. Particularly, for high-viscosity oils that are challenging to absorb, TiVCTX/GAs demonstrate remarkable absorption ability by reducing their viscosity through photothermal heating. Overall, TiVCTX/GAs show great promise as versatile adsorbents and absorbers for efficiently and comprehensively removing various organic contaminants from wastewater.
Yuming Zhang,Dongdong Li,Junzhi Li,Yilin Li,Lili Wang,Hao Xu,Wei Han
Magnesium-based battery system has emerged as the potential candidate to beyond Li-ion battery system due to the numerous advantageous of magnesium anode, such as natural abundance, high capacity and dendrites free. However, the selection of cathode materials and the intercalation of magnesium-ions in the cathode host material remains a challenge due to the strong interaction of highly polar divalent magnesium ions with the cathode material, making the diffusion of magnesium ions relatively difficult. Herein, the flexible TiVCT x MXene film was developed via a facile and economical approach. As the cathode host material for magnesium-ion storage, the freestanding TiVCT x MXene film displays a high specific capacity of 111 and 135 mAh g −1 at a current density of 0.05 A g −1 for magnesium-ion batteries (MIB) and Mg/Li hybrid batteries (MLHB). Furthermore, a long-term cycling stability over 1000 cycles was demonstrated and a detailed investigation of the unique long activation phenomenon of MXene films during cycling. More importantly, the reaction mechanism of magnesium-ion storage was validated, i.e., the MXene interlayer spacing variation with the reversible Mg 2+ diffusion behavior. This work reveals the magnesium storage mechanism of MXene materials and provides a new pathway for high-performance storage of magnesium-ion cathode materials.
Yuming Zhang,Jun-Ming Cao,Zeyu Yuan,Hao Xu,Dongdong Li,Yilin Li,Wei Han,Lili Wang
Magnesium-ion batteries (MIB) have gradually attracted attention owing to their high theoretical capacity, high safety, and low cost. A bimetallic metal–organic framework self-sacrificing template and a co-assembly strategy are used to prepare a high-performance, stable cycling NiSe 2 -CoSe 2 @TiVCT x (NCSe@TiVC) heterostructure MIB cathode that can be used as a flexible integrated unit to power future self-powered systems. Benefiting from the synergistic effect of TiVCT x MXene and NCSe, the NCSe@TiVC heterostructure electrode has a discharge-specific capacity of 136 mAh g −1 at 0.05 A g −1 and high cycling stability of over 500 cycles; the assembled pouch-cell device as flexible integrated unit exhibits good practicability. The magnesium ion storage mechanism is also validated using quantitative kinetic analysis, ex situ XRD, and XPS techniques. Density functional theory analysis indicates the most stable Mg-atom adsorption sites in the heterostructure. This study broadens the possibilities for applying the TiVCT x MXene heterostructure to energy storage materials and future self-powered flexible systems.
危险品化学品经营许可证（带存储）