Three photosensitive tert-butylcalixnarene (TBCn, n = 4, 6, 8)-protected titanium-oxo clusters (TOCs), formulated as Ti4(μ3-O)2(TBC4)2(O i Pr)4(DEF)2·DEF (1, TBC4-Ti 4 , DEF = ...N,N-diethylformamide), Ti4(μ4-O)TBC6(OCH3)9·H2O (2, TBC6-Ti 4 ), and Ti4(μ3-O)2(O i Pr)4TBC8(DEF)2·DEF (3, TBC8-Ti 4 ), were successfully synthesized and characterized. Because of the generation of charge transfer from TBCn to the TiO core, the three TBCn-decorated TOCs show a broadened visible-light absorption and narrowed optical band gap based on the UV–visible spectra and density functional theory calculations. The corresponding photosensitive electrodes prepared using these three TOCs exhibit stable photocurrent responses. Furthermore, their photocatalytic performances for hydrogen evolution and methylene blue degradation were evaluated, and all of the materials display excellent photocatalytic activity and stability. The calixarene-Ti coordination is therefore an effective strategy to enlarge the visible-light absorption band of Ti–O materials and improve their photoelectric/photocatalytic performances.
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IJS, KILJ, NUK, PNG, UL, UM
Rechargeable aqueous zinc‐ion batteries (ZIBs) have attracted escalating attention recently, owing to their energy density, decreasing cost, advanced safety, and environmental benignity. ...Nevertheless, ZIBs still lack suitable cathode materials with stable cycling performance, owing to the high polarization of zinc ion. Therefore, developing candidate materials with excellent properties remains a great challenge. Herein, we successfully synthesize a novel Mn3O4@N‐doped carbon matrix composite nanorods (Mn3O4@NC Nrs) by using MnOOH nanorods (the self‐sacrifice templates) and polypyrrole (carbon and nitrogen source). Benefiting from the N‐doped carbon shell and the synergetic effect of Zn2+ and Mn2+ in the electrolyte, the Mn3O4@NC Nrs show superior cycling stability and long cycling features for ZIBs. Specifically, the zinc cell conducts a high reversible capacity of 280 mAh g−1 at 100 mA g−1 and retains a high reversible capacity of 97 mAh g−1 at 1000 mA g−1 after 700 cycles. In addition, the work provides a new approach to fabricate long‐term and high‐rate capability cathodes for ZIBs.
Rod for your own back: Mn3O4 on a new type of N‐doped carbon matrix support is prepared as a cathode material for zinc‐ion batteries. The N‐doped carbon matrix can relieve volume expansion and enhance the electron conductivity during the charge‐discharge process. Therefore, the Mn3O4@NC composite nanorods exhibit excellent electrochemical performances.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Biomass-derived mesoporous carbon materials (MCMs) with high specific surface area and pore volume were prepared from waste litchi shells using KOH activation method. Furthermore, the Mn3O4 particles ...were designed to coat the homemade MCM4 (WMCMs:WKOH=1:4), which exhibited enhanced electrochemical behavior as cathode materials for aqueous zinc ion batteries (AZIBs). In addition, the diffusion coefficient of Zn2+ was calculated by cyclic voltammetry, revealing that the electrochemical process of a cell is affected by Zn2+ ions diffusion. The batteries exhibited an excellent cyclic performance through the effective synergy between Mn3O4 and MCM4, which provides a feasible scheme for the development of low-cost and eco-friendly cathode materials for AZIBs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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The development of zinc-ion storage cathode materials for aqueous zinc-ion batteries (AZIBs) is a necessary step for the construction of large-scale electrochemical energy conversion ...and storage devices. Iron-doped alpha-manganese dioxide (α-MnO2) nanocomposites were achieved in this study via pre-intercalation of Fe3+ during the formation of α-MnO2 crystals. A polypyrrole (PPy) granular layer was fabricated on the surface of α-MnO2 using acid-catalyzed polymerization of pyrroles. The pre-intercalation of Fe3+ effectively enlarges the lattice spacing of α-MnO2 and consequently decreases the hindrance for Zn2+ insertion/extraction in the iron-doped α-MnO2 coated by PPy (Fe/α-MnO2@PPy) composite. Meanwhile, the PPy buffer layer can ameliorate electron and ion conductivity and prevent dissolution of α-MnO2during the charge/discharge process. This unique structure makes the Fe/α-MnO2@PPy composite an efficient zinc-ion storage cathode for AZIBs. The targeted Fe/α-MnO2@PPy cathode achieves superior performance with reversible specific capacity (270 mA h g−1 at 100 mA g−1) and exhibits highdiffusioncoefficientof 10−10–10−14 cm−2 s−1. Therefore, a feasible approach is implemented on advanced electrode materials using in AZIBs for practical applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Herein, a synthetic strategy for a rough microsphere Cr(VI)-adsorbent via the reaction of tannic acid (TA) and 1,6-hexanediamine (HA) and using polyethylene glycol (PEG) as surface modifier was ...presented. This adsorbent was characterized by a Fourier Transform Infrared spectrometer (FTIR), thermogravimetic analysis (TGA), X-ray photoelectron spectroscopy (XPS), etc. Certain factors, including contact time, PEG@poly(tannin-1,6-hexanediamine) (PEG@PTHA) dosage, initial concentration, and experimental temperature affecting the Cr(VI) adsorption performance of adsorbent were explored. PEG@PTHA can adsorb Cr and the Cr(VI) was reduced up to Cr(III) due to the existence of phenolic hydroxyl groups. Its adsorption capacity can reach up to 300 mg/g within 10 min and approximately 100% removal percentage below the initial concentration of 100 mg/L. Its behavior matched well with the Langmuir isotherm model and pseudo-second-order kinetic model. A PEG@PTHA adsorbent with maximum adsorption capacity (450 mg/g) has great prospects in Cr(VI)-sewage treatment.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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•The NHCSs@MnO2 composite microspheres were prepared by the simple approach.•The cycling performance of NHCSs@MnO2 shows an excellent reversible capacity of 206 mA h g−1.•The specific ...capacity can be tending towards stability (103 mA h g−1) at 500 mA g−1 over 650 cycles.•The Zn2+ insertion/extraction mechanism is confirmed in NHCSs@MnO2 electrode.
The growing demand for energy storage devices leads to great interest in advanced batteries researches. Among them, aqueous rechargeable zinc ion batteries (ARZIBs) has attracted wide attention due to their low cost, simple manufacturing process and environmental friendliness. Here, we prepared a composite material, namely MnO2 particles grown on the surface of N-doped hollow porous carbon nanospheres, that is, combining hollow carbon material with metal oxides, and employed it as the cathode of ARZIBs. Owing to the synergistic merits of desirable structural features of manganese oxides and hollow porous carbon nanospheres, the composite material exhibited excellent performance for the storage of zinc ions, including high capacity of 206 mA h g−1 at 100 mA g−1, impressive rate capability of 103 mA h g−1 at 500 mA g−1 and superior cycling stability with the coulombic efficiency (capacity retention) of 98.3% over 650 cycles. The distinguished electrochemical behavior is attributed to the synergistic effects of desirable structural features of manganese oxides and hollow porous carbon nanospheres, which can be summed up as larger electron modified interface, high mass loading, and stable carbon-layer structure. These results demonstrate that the composite material could satisfy the criteria for applying in advanced ARZIBs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Manganese dioxide as the electrode for aqueous zinc-ion batteries (AZIBs) is influenced by the material dissolution. Herein, β-MnO
2
/N-doped carbon matrix (NCm) or Mn
5
O
8
/NCm composites were ...fabricated by effective synthesis process using polyaniline (PANI) as carbon/nitrogen sources. The conductive N-doped carbon layer was tied to β-MnO
2
, which increased the electrical conductivity of the β-MnO
2
nanorod. At current densities of 200 mA g
−1
, the β-MnO
2
/NCm electrode delivered a higher discharge capacity of 331 mAh g
−1
comparing with 185 mAh g
−1
for the pure β-MnO
2
electrode. Besides, the Mn
5
O
8
/NCm electrode could provide a discharge capacity of 266 mAh g
−1
. Therefore, the approach in this study may pave the way on preparing manganese oxides/NCm materials for AZIBs.
Rechargeable aqueous zinc-ion batteries (ZIBs) have been receiving much attention because they are cheap, safe, and environment-friendly. However, their application is bottlenecked by limitation in ...high-capacity cathode and types of materials to achieve satisfactory cyclability. Therefore, developing new cathode materials for rechargeable zinc-ion batteries is essential. Herein, we report promising ZIBs based on metal-organic framework-derived 2-methylimidazole zinc salt (ZIF-8)/Mn2O3 nanocomposites as cathode and zinc as the anode. ZnMn2O4/Mn2O3 bi-component nanorods were synthesized by annealing ZIF-8/MnO2 precursors, which showed a reversible discharge capacity of 230 mAh g–1 at 100 mA g–1 after 120 cycles and a high capacity of 80 mAh g–1 at a large current density of 1000 mA g–1. The superior zinc storage performance is attributed to the synergistic effect between ZnMn2O4 and Mn2O3.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•A novel cathode material prepared (Mn5O8/rGO) by the solution-phase method.•A H+/Zn2+ coinsertion mechanism of manganese oxide cathode was elucidated.•The addition of reduced graphene oxide enhances ...the cycling stability.•The Mn5O8/rGO cathode exhibits a high specific capacity with excellent rate and cyclic performance.
Due to the higher requirements of energy storage equipment, aqueous rechargeable zinc ion batteries (ARZIBs) with the advantages of environmental friendliness, low cost and simple preparation have attracted wide attention. In this study, the composites of Mn5O8 uniformly deposited on the surface of graphene used as cathode of ARZIBs are synthesized. Owing to the hierarchically porous morphology, the electrode delivers a high reversible capacity of 260 mA h g−1 at a current density of 100 mA g−1 and shows excellent long-term cycling stability of up to 1000 cycles with a capacity retention of 98.8%. In addition, the energy storage mechanism of H+ and Zn2+ coinsertion was tentatively studied as well. And this study provides some inspiration of designing high-performance ARZIBs for grid-scale energy storage.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Zinc-ion batteries have been received extensive interest in the resulting energy storage devices due to their high safety, simple operation, environment friendliness and nontoxicity. Herein, we ...report a composite material of manganese sulfide/reduced graphene oxide (MnS/RGO) as the cathode materials for aqueous zinc-ion batteries, which exhibits excellent cycling performance. Owing to the synergistic effect of desirable structural characteristic of MnS microsphere and favorable conductivity of the graphene network, the composite material delivers remarkable zinc storage performance. The MnS/RGO electrode exhibits a reversible discharge capacity of 289 mA h g−1 at 100 mA g−1, and impressive rate capability of 62 mA h g−1 at 1000 mA g−1. The brilliant electrochemical performance of MnS/RGO is related to the RGO nanosheets, which greatly improves the electrical contact and effectively alleviates the huge volume expansion during charging and discharging.
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•The synthetic method is green and effective.•The MnS/RGO composite material was first reported as the cathode material for aqueous zinc-ion batteries.•The cathode materials exhibit excellent rate ability.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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