Efficient Sunlight-Induced Methylene Blue Removal over One-Dimensional Mesoporous Monoclinic BiVO4 Nanorods

Sunlight-driven mesoporous BiVO4 nanorods with monoclinic structure have been successfully synthesized via a simple hydrothermal method. The as-prepared one-dimensional BiVO4 nanorods exhibited high specific surface area due to their unique mesoporous structure. The mesoporous BiVO4 nanorods possessed strong photoabsorption properties in the visible light region as well as the ultravisible region, and the band gap was estimated to be ca. 2.18 eV. The photocatalytic activities were evaluated by decolorization of methylene blue under sunlight irradiation. Photocatalytic tests demonstrated that the decolorization rate of as-prepared mesoporous BiVO4 nanorods was even up to 98.8% in 180 min, much better than that prepared by solid-state reaction (23.1%) and the commercial TiO2 (Degussa P25) (14.2%) under the same conditions, due to their higher specific surface area and appropriate band gap. Moreover, the unique BiVO4 nanorods exhibit high stability after five photocatalytic degradation recycles

Green interfacial synthesis of two-dimensional poly(2,5-dimethoxyaniline) nanosheets as a promising electrode for high performance electrochemical capacitors

National Natural Science Foundation of China [51202004]; Natural Science Foundation of Anhui Province [KJ2013A051]; CAS Key Laboratory of Materials for Energy Conversion [2014001]2D poly(2,5-dimethoxyaniline) nanosheets were first designed and tailored as intriguing pseudo-capacitive electrode for advanced supercapacitors via green interfacial synthetic strategy, and yielded large specific capacitance (SC) and remarkable SC retention at high rates in 1 M HCl electrolyte

Polymer-assisted synthesis of a 3D hierarchical porous network-like spinel NiCo2O4 framework towards high-performance electrochemical capacitors

National Natural Science Foundation of China [51202004, 21173120]; Nature Science Foundation of Anhui Province [KJ2013A051]; Specialized Research Fund for the Doctoral Program of Higher Education of China [20060287026]; Nature Science Foundation of Jiangsu Province [BK2011030]; Foundation of Key Laboratory of Colloid and Interface Chemistry (Shandong University), Ministry of Education [201201]We have developed a facile yet scalable polymer-assisted chemical solution route to prepare a three-dimensional (3D) hierarchical porous network-like NiCo2O4 framework for advanced electrochemical capacitors (ECs). The unique interconnected hierarchical porous framework is constructed by nanosized spinel NiCo2O4 building blocks of 20-30 nm size, thus, a 3D continuous electron transport expressway, convenient electrolyte penetration-diffusion and large electrode-electrolyte interface are obtained simultaneously. The combination of these appealing structural features in the striking network-like NiCo2O4 framework results in a drastically enhanced kinetic behavior, large specific capacitance (SC) and a remarkable cycling stability at high rates. The unique network-like NiCo2O4 electrode features a SC of 587 F g(-1) at 2 A g(-1), and can deliver up to 518 F g(-1) at a large current density of 16 A g(-1). Also, a SC deterioration of similar to 6% of the maximum SC is evident after continuous 3500 charge-discharge cycles at varying current densities, ranging from 2 to 16 A g(-1). Furthermore, the synthetic strategy presented here can be easily extended to fabricate other binary complex metal oxides and/or ternary metal oxides with a controlled composition and porous structure, which may be promising candidates for high-performance ECs, and even advanced Li-ion batteries

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

National Natural Science Foundation of China [51202004]; Nature Science Foundation of Anhui Province [KJ2013A051]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 submicrospherical 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

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

National Natural Science Foundation of China [51202004]; Natural Science Foundation of Anhui Province [KJ2013A051]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 similar to 90% over continuous 3000 charge-discharge cycles at a current density of 6 A g(-1) confirmed 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

Enhanced Supercapacitance of Hydrous Ruthenium Oxide/Mesocarbon Microbeads Composites toward Electrochemical Capacitors

A facile hydrothermal strategy was proposed to synthesize RuO2⋅nH2O/mesocarbon microbeads (MCMBs) composites. Further physical characterizations revealed that RuO2⋅nH2O nanoparticles (NPs) were well dispersed upon the surfaces of the MCMB pretreated in 6 M KOH solution. Electrochemical data indicated that the RuO2⋅nH2O/MCMB composites owned higher electrochemical utilization of RuO2 species, better power property, and better electrochemical stability, compared with the single RuO2 phase. The good dispersion of RuO2⋅nH2O NPs and enhanced electronic conductivity made the H+ ions and electrons easily contact the RuO2⋅nH2O phase for efficient energy storage at high rates

Facile Solvothermal Synthesis of Hollow BiOBr Submicrospheres with Enhanced Visible-Light-Responsive Photocatalytic Performance

In this work, hierarchical hollow BiOBr submicrospheres (HBSMs) were successfully prepared via a facile yet efficient solvothermal strategy. Remarkable effects of solvents upon the crystallinities, morphologies, and microstructures of the BiOBr products were systematically investigated, which revealed that the glycerol/isopropanol volumetric ratio played a significant role in the formation of hollow architecture. Accordingly, the underlying formation mechanism of the hollow submicrospheres was tentatively put forward here. Furthermore, the photocatalytic activities of the resulting HBSMs were evaluated in detail with photocatalytic degradation of the organic methyl orange under visible light irradiation. Encouragingly, the as-obtained HBSMs with striking recyclability demonstrated excellent visible-light-responsive photocatalytic performance, which benefits from their large surface area, effective visible light absorption, and unique hollow feature, highlighting their promising commercial application in waste water treatment

Facile Construction of Porous ZnMn₂O₄ Hollow Micro-Rods as Advanced Anode Material for Lithium Ion Batteries

Spinel ZnMn2O4 is considered a promising anode material for high-capacity Li-ion batteries due to their higher theoretical capacity than commercial graphite anode. However, the insufficient cycling and rate properties seriously limit its practical application. In this work, porous ZnMn2O4 hollow micro-rods (ZMO HMRs) are synthesized by a facile co-precipitation method coupled with annealing treatment. On the basis of electrochemical analyses, the as-obtained samples are first characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and scanning electron microscopy techniques. The influences of different polyethylene glycol 400 (PEG 400) additions on the formation of the hollow rod structure are also discussed. The abundant multi-level pore structure and hollow feature of ZMO HMRs effectively alleviate the volume expansion issue, rendering abundant electroactive sites and thereby guaranteeing convenient Li+ diffusion. Thanks to these striking merits, the ZMO HMRs anode exhibits excellent electrochemical lithium storage performance with a reversible specific capacity of 761 mAh g−1 at a current density of 0.1 A g−1, and a long-cycle specific capacity of 529 mAh g−1 after 1000 cycles at 2.0 A g−1 and keep a remarkable rate capability. In addition, the assembled ZMO HMRs-based full cells deliver an excellent rate capacity, and when the current density returns to 0.05 A g−1, the specific capacity can still reach 105 mAh g−1 and remains at 101 mAh g−1 after 70 cycles, maintaining a material-level energy density of approximately 273 Wh kg−1. More significantly, such striking electrochemical performance highlights that porous ZMO HMRs could be a promising anode candidate material for LIBs

Confining sulfur in double-shelled hollow carbon spheres for lithium-sulfur batteries

Going into their shell: A novel carbon-sulfur nanocomposite has been synthesized by confining sulfur in double-shelled soft carbon hollow spheres (see figure) with high surface area and porosity. This carbon-sulfur nanocomposite shows outstanding electrochemical performance when evaluated as a cathode material for lithium-sulfur batteries