31 pubs · 598 cites · h-index 13
Context & scaleZn-based batteries with aqueous electrolytes are garnering great interest as the most promising next-generation batteries due to their intrinsic high safety, low cost, and environmental friendliness. However, the short cycle life of the Zn battery, originating from the low reversibility of the Zn metal electrode, is far from satisfactory. To achieve high reversibility of Zn metal electrode, tackling the water decomposition reaction and the inhomogeneous deposition/dissolution reaction is crucial. We present design principles for aqueous co-solvent electrolytes with high Zn reversibility and suggest a new parameter for accurately selecting beneficial organic molecules for Zn-based batteries. Electrolytes prepared using this principle effectively overcome the challenges in aqueous systems and demonstrate record-high cycling stability. This work provides new insight into aqueous electrolyte systems.Highlights•Thorough electrolyte design principles are suggested for aqueous batteries•An effective descriptor for selecting organic co-solvent is discovered•Designed electrolyte provides high reversibility and cycling stability of Zn batteriesSummaryPolarity scales are often used as descriptors for selecting organic molecules for aqueous Zn battery (AZB) electrolytes. However, failure to accurately predict the solvation of Zn2+ raises questions about their applicability for designing high-performance AZB electrolytes. Here, Dimroth and Richardt's Et(30) polarity scale is introduced as an effective guideline for screening organic molecules. A clear volcanic correlation is demonstrated between Et(30) and Zn Coulombic efficiency (CE). This challenges the common consensus in the aqueous electrolyte design formula, which typically uses highly polar organic molecules to improve Zn CE, and indicates that the roles of organic molecules beyond altering the Zn2+ solvation structure are critical for obtaining high AZB performances. Based on the Et(30) scale, the designed electrolyte achieves a high average Zn CE (99.8%), an exceptionally long cycle life (5,500 h), and a high specific energy (110 Wh kg?1). Et(30) polarity scale offers general frameworks for selecting organic molecules in aqueous electrolytes.
The discharge of chromium-containing wastewater in industrial production causes resource loss and damage to the ecological environment. Currently, various phenolamine materials have been used to remove chromium, but their harsh adsorption conditions bring many difficulties. For example, ideal chromium removal is only achieved at low pH. In this study, we synthesized catechol/m-phenylenediamine nanospheres (CMN) and combined CMN with Fe(II) for Cr removal from aqueous solutions, and Fe(II) comes from FeSO4·7H2O. CMN was characterized and analyzed by field-emission scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), Fourier transformed infrared (FTIR), X-ray diffraction (XRD), X-ray photoelectron (XPS). The adsorption performance was studied through a series of adsorption experiments. When C0 = 900 mg/L and pH = 6, the maximum adsorption capacity obtained in the experiment was 977.1 mg/g. It maintains excellent adsorption properties in acidic, neutral and alkaline environments. The results of the adsorption mechanism showed that the ultra-high adsorption capacity of CMN and Fe(II) for Cr was the result of the synergistic effect of adsorption and reduction, including electrostatic attraction, reduction and coprecipitation. CMN is expected to be an ideal adsorbent for Cr removal in aqueous solution due to its low cost, high biocompatibility and high efficiency in Cr removal.
The large-scale use of antibiotics is causing serious water pollution problems, and it is of great significance to develop new technologies to remove antibiotics from water. As an environmentally friendly and economical adsorption material, carbon derived from biomass is a low-cost and feasible material for removing antibiotics in sewage, but the current removal efficiencies are not high enough for large-scale practical application. In this study, poplar wood chips are used as raw material, and a magnetic biochar is prepared by co-pyrolysis of poplar wood chips and FeCl3/CaCl2 mixed molten salt. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2-isothermal adsorption and desorption, X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) techniques showed the successful synthesis of Fe2O3/bioC composite. In-situ formed Fe2O3 makes the biochar possess the characteristic of superparamagnetic, which is conducive to the recycling of biochar. Due to the etching effect of the molten salts, rough surface was formed on Fe2O3/bioC, resulting in a maximum norfloxacin (NOR) adsorption ability up to 38.77 mg g−1 at pH 6.0. The NOR adsorption behavior on Fe2O3/bioC followed the pseudo second order kinetic model and the equilibrium data was best fitted the Langmuir model. In addition, the adsorption process of NOR on Fe2O3/bioC was thermodynamically spontaneous. The results show that this low-cost and reusable magnetic biochar has the potential for rapid and efficient removal of antibiotic from aqueous solution.
Combining metallic and ceramic properties, and as precursors for MXenes, MAX phases have attracted extensive attention. In recent years, A-element substitution has been demonstrated as an effective scheme to enrich the MAX family. To explore more possible MAX members, the structural, mechanical, and electronic properties and stabilities of 31 Ti3AC2 (A = Al, Si, P, S, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, Os, Ir, Pt, Au, Hg, TI, Pb, Bi, and Po) configurations are investigated in this work. Moreover, the interfacial strength implicating the possibility of exfoliating MAX into MXenes is examined. The A-element plays a crucial role in the lattice parameters and mechanical strength of Ti3AC2, and their variations are well explained by the synergistic effects of d–d and p–d hybridizations between the valence orbitals of Ti and A. Ti3SC2 presents the largest Young’s modulus of 360 GPa, which is 6.82% higher than that in the well-studied Ti3SiC2. Ti3SbC2 is a mechanical quasi-isotropic configuration. After checking the mechanical, dynamical, and thermodynamic stability, Ti3AC2 (A = Al, Si, P, S, Ga, Ge, As, Cd, In, Sn, Sb, Au, Hg, Pb, TI, and Po) are stable, while Ti3AC2 (A = Fe, Co, Zn, Se, Ru, Rh, Pd, Ag, Te, Ir, Pt, and Bi) are metastable. Compared to Ti3AlC2, Ti3AC2 (A = Ag, Sb, Te, Bi, and Po) exhibit much lower interfacial strength in Ti–A interfaces and larger ratios between the interfacial strengths of neighboring Ti–C and Ti–A interfaces. This implies that these configurations are promising precursors for the synthesis of Ti3C2Tx (Tx denotes surface groups) with a large flake size. All of the configurations are metallic, and Ti3AC2 (A = Fe and Co) are magnetic. Based on the phonon dispersion and electronic structure, these Ti3AC2 configurations might have potential applications in phononic crystals and topological materials.
A new cadmium metal–organic framework [Cd(IsoNDI)(ClO4)·H2O]n (ZH-102, IsoNDI = N,N′-di(4-pyridylacylamino)-1,4,5,8-naphthalene diimide) has been synthesized under solvothermal conditions and characterized systematically by elemental analyses, IR spectroscopy, powder X-ray diffraction, and thermogravimetric analyses. Single-crystal X-ray diffraction analysis reveals that ZH-102 exhibits a 2D structure similar to a ‘safety fence’ that further stacks into a 3D supramolecular network, which is constructed by bridging of Cd–IsoNDI with perchlorate (ClO4−) anions and intermolecular interaction. Owing to the presence of electron-deficient NDI moieties and the generation of IsoNDI radicals, ZH-102 displays reversible photochromic properties under irradiation and heating (120 °C) and photocontrolled luminescence properties. In particular, ZH-102 also exhibited vapochromic behavior for detecting amines. Moreover, the ZH-102 showed that excellent heat causes hydrochromism properties with a color change from deep yellow to coffee color when heated at 200 °C. Therefore, ZH-102 possesses multiple chromic properties and could be used as a colorimetric sensor, which provides a new route to design functional MOFs.
A novel metal-organic hybrid photochromic compound [Zn (CV) (L2)]·2H2O (1) (CV = N,N'-4,4'-bipyridiniodipropionate, H2L2 = isophthalic acid) has been synthesized solvothermally. Compound 1 features a two-dimensional (2D) framework structure, exhibiting photochromic properties under sunlight and UV irradiation with an obvious color change from colorless to dark blue. Meanwhile, the luminescence properties of 1 were investigated, and the results suggested that 1 has good properties of detecting dichromate ions. Furthermore, compound 1 shows different color changes when exposed to different alkyl-amines, and 1 can also be deposited into paper to use as portable test strips. This work can be applied to practical applications as a multifunctional detector against light and chemicals.
Two novel Cd-CPs based on a new viologen ligand exhibiting photochromism, thermochromism, photocontrolled luminescence properties, thermocontrolled luminescence properties and ammonia detection.
The “reversible” photochromism of polyoxomolybdate–viologen hybrids can be achieved without proton transfer, and the weak electron-withdrawing ability of viologen favors photoreduction of Mo( vi ).
The photochromism of three MOFs based on NDI chromophores is mainly induced by two kinds of non-covalent intermolecular interactions.
The different photochromic properties of two naphthalenediimide-based isometric compounds are derived from two lone pair–π interactions with varying strengths.