Lin Lian

Template-engaged synthesis of uniform mesoporous hollow NiCo2O4 sub-microspheres towards high-performance electrochemical capacitors

An efficient template-engaged synthetic strategy, where silica spheres were applied as hard templates, was developed to synthesize hierarchical mesoporous hollow NiCo2O4 sub-microspheres assembled entirely from ultrathin nanosheets with a thickness of a few nanometers. The as-prepared mesoporous hollow NiCo2O4 sub-microspheres are very uniform in size, mesoporous in textual property, and structurally robust benefiting from the in situ template removal. The morphologies of the hollow sub-microspherical architecture can be tuned easily by varying the concentrations of Ni2+, Co2+, and the precipitant. When evaluated as an appealing electroactive material for electrochemical capacitors (ECs), the as-fabricated hierarchical hollow NiCo2O4 sub-microspheres delivered a specific capacitance (SC) of 678 F g−1 at a current density of 1 A g−1, and even kept it as high as 540 F g−1 at 10 A g−1. Additionally, a desirable cycling stability of 13% SC degradation over 3500 continuous cycles at a current density of 10 A g−1 is observed, suggesting their promising application in advanced ECs.

Scalable Room‐Temperature Synthesis of Mesoporous Nanocrystalline ZnMn2O4 with Enhanced Lithium Storage Properties for Lithium‐Ion Batteries

In this work, we put forward a facile yet efficient room-temperature synthetic methodology for the smart fabrication of mesoporous nanocrystalline ZnMn2O4 in macro-quality from the birnessite-type MnO2 phase. A plausible reduction/ion exchange/re-crystallization mechanism is tentatively proposed herein for the scalable synthesis of the spinel phase ZnMn2O4. When utilized as a high-performance anode for advanced Li-ion battery (LIB) application, the as-synthesized nanocrystalline ZnMn2O4 delivered an excellent discharge capacity of approximately 1288 mAh g(-1) on the first cycle at a current density of 400 mA g(-1), and exhibited an outstanding cycling durability, rate capability, and coulombic efficiency, benefiting from its mesoporous and nanoscale structure, which strongly highlighted its great potential in next-generation LIBs. Furthermore, the strategy developed here is very simple and of great importance for large-scale industrial production.

Rapid low-temperature synthesis of mesoporous nanophase ZnFe2O4 with enhanced lithium storage properties for Li-ion batteries

In this work, a rapid low-temperature and cost-effective refluxing synthesis strategy was elegantly designed, and elaborately developed for high-yield fabrication of mesoporous nanocrystalline ZnFe2O4 with nano-scaled size of ∼7 nm, desirable mesoporosity and large specific surface area. Benefitting from these admirable nanostructured architectures, the as-derived nanophase ZnFe2O4 exhibited excellent discharge capacity of 1322 mA h g−1 on the first cycle, and showed outstanding cycling durability, rate capability, and coulombic efficiency even at high current rates when evaluated as an anode for Li-ion batteries. More importantly, a low temperature of 100 °C and short reaction time of 5 h were applied here; therefore, the efficient synthetic strategy we proposed herein is advocated for scaled-up commercial application.

Green Template‐Free Synthesis of Hierarchical Shuttle‐Shaped Mesoporous ZnFe2O4 Microrods with Enhanced Lithium Storage for Advanced Li‐Ion Batteries

In the work, a facile and green two-step synthetic strategy was purposefully developed to efficiently fabricate hierarchical shuttle-shaped mesoporous ZnFe2 O4 microrods (MRs) with a high tap density of ∼0.85 g cm(3) , which were assembled by 1D nanofiber (NF) subunits, and further utilized as a long-life anode for advanced Li-ion batteries. The significant role of the mixed solvent of glycerin and water in the formation of such hierarchical mesoporous MRs was systematically investigated. After 488 cycles at a large current rate of 1000 mA g(-1) , the resulting ZnFe2 O4 MRs with high loading of ∼1.4 mg per electrode still preserved a reversible capacity as large as ∼542 mAh g(-1) . Furthermore, an initial charge capacity of ∼1150 mAh g(-1) is delivered by the ZnFe2 O4 anode at 100 mA g(-1) , resulting in a high Coulombic efficiency of ∼76 % for the first cycle. The superior Li-storage properties of the as-obtained ZnFe2 O4 were rationally associated with its mesoprous micro-/nanostructures and 1D nanoscaled building blocks, which accelerated the electron transportation, facilitated Li(+) transfer rate, buffered the large volume variations during repeated discharge/charge processes, and provided rich electrode-electrolyte sur-/interfaces for efficient lithium storage, particularly at high rates.

Microwave-assisted interfacial hydrothermal fabrication of hydrophobic CdWO4 microspheres as a high-performance photocatalyst

In this work, we successfully developed a facile yet efficient microwave-assisted interfacial hydrothermal strategy to fabricate CdWO4 microspheres with a hydrophobic surface as an advanced photocatalyst for photocatalytic degradation of the dye Methyl Orange (MO) under ultraviolet (UV) light irradiation. The as-synthesized CdWO4 microspheres exhibited excellent photocatalytic degradation efficiency of 100% under UV illumination for 80 min, benefiting from its appropriate band gap, strong UV absorption, hydrophobic surface, and low recombination rate of photo-generated charge carriers. The striking stability and easy separation of the unique CdWO4 microspheres further promised its practical recycling usage. Also, insights into the formation and degradation mechanisms of CdWO4 microspheres were tentatively proposed.

Facile synthesis of Co2P2O7 nanorods as a promising pseudocapacitive material towards high-performance electrochemical capacitors

In the present work, we developed an efficient one-step template-free strategy to fabricate intriguing one-dimensional (1D) Co2P2O7 nanorods (NRs) at room temperature, and utilized the unique monoclinic Co2P2O7 NRs as an excellent electrode material for high-performance pseudocapacitors using 3 M KOH as an electrolyte. Strikingly, the as-synthesized 1D Co2P2O7 NR electrode delivered a specific capacitance (SC) of 483 F g−1 at 1 A g−1, and even at 402 F g−1 a high current loading of 10 A g−1. And the SC retention of ∼90% over continuous 3000 charge–discharge cycles at a current density of 6 A g−1confirmed its stable long-term cycling ability at high current density. More significantly, the underlying electrochemical energy-storage mechanism of the Co2P2O7 NR electrode in alkaline KOH aqueous solution was tentatively proposed. And the appealing strategy was proposed for future exploration and development of other low-cost pseudocapacitive materials for next-generation ECs.