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Abstract: Multi-channel visible and near-infrared (NIR) emission transitions originating from 4G5/2 emitting state of Sm3+ in cadmium-aluminum-silicate (CAS) glasses with maximum-phonon-energy of ∼980cm−1 have been investigated. Based on the measured absorption spectrum, the Judd–Ofelt parameters Ω t (t=2, 4, 6) are derived to be 2.87×10−20, 3.34×10−20 and 1.86×10−20 cm2, respectively. From the evaluated Judd–Ofelt parameters, the radiative parameters such as spontaneous emission probabilities (A rad), branching ratios (β), and radiative lifetime (τ rad) are obtained from the 4G5/2 excited level to different lower energy levels. The efficient visible and NIR transition emissions have been observed in the Sm3+ doped CAS glasses, and the maximum stimulated emission cross-sections (σ e-max) corresponding to emission peaks are calculated and demonstrated to lay in the same order of magnitude. The quantum efficiency of 4G5/2 level of Sm3+ has been derived to be 60%. Investigations on multi-channel radiative transition emissions originated from 4G5/2 level of Sm3+ in CAS glasses expose its potential applications in tunable laser, medical light source and NIR optoelectronic devices. [Copyright &y& Elsevier]

Porous TiO 2 nanomaterials assembled by anatase TiO 2 nanoparticles are successfully synthesized via a simple method with the assistance of an easily accessed biomass-sodium alginate. The alginate is favorable for the formation of small TiO 2 nanoparticles and the presence of SO 4 2- in the precursors could prevent crystal phase transformation from anatase to rutile to a certain extent during high-temperature calcination process. The pyrolysis product of alginate ions could also prevent the formation of large TiO 2 nanoparticles. The reactant concentrations and the ratio of sodium alginate and Ti(SO 4) 2 play important roles in the surface area and pore volume of porous TiO 2 nanomaterials. The porous TiO 2 nanomaterials are used as anode materials for lithium ion batteries and possess a reversible capacity of 223 mAh g−1 at 1C after 20 cycles. Further increasing the cycling rates, the relatively large reversible capacities still maintain. The efficient nanostructures and good crystallinity of porous TiO 2 nanomaterials result in their superior electrochemical behavior. Image 1 • Porous TiO 2 nanomaterials prepared with the assistance of biomass resource. • Porous TiO 2 nanomaterials as anode material. • Hierarchical porous nanostructures enhance electrochemical performance. [ABSTRACT FROM AUTHOR]

Hierarchical three-dimensional graphene-based carbon materials have been successfully prepared via a template-assisted approach. It is found that the structure, morphology, graphitization degree, surface area and pore volume for the obtained carbon materials could be easily controlled by adjusting the amount of reactant and template. The results show that the obtained hierarchical nanostructured carbon material possesses a very stable reversible capacity of 395 mAh g−1 at 1C and exhibits extremely high reversible capacity of 163 mAh g−1 at the high rate of 20C. The large macroporous network and small mesopores in the materials can facilitate electrolyte and lithium ion transportation. The hollow carbon nanoparticles composed of stacked graphene can favor the electron diffusion within the materials. The micropores in the carbon materials can also increase the reversible capacity. Image 1 • The amounts of reactants and templates affect the graphene-based carbon materials. • Hierarchical three-dimensional graphene-based carbon materials as anode material. • Hollow nanoparticles composed of stacked graphene improve electrochemical behaviors. [ABSTRACT FROM AUTHOR]

The fabrication of sulfide/graphene composites is an important strategy to improve the performance of supercapacitors. It is still a challenge to synthesize three-dimensional sulfide/graphene nanostructures with special morphologies and structures because it is difficult to realize the effective arrangement of graphene. In this work, a simple method has been successfully developed for the fabrication of three-dimensional NiS 2 /graphene nanostructures. The rod-like morphology of the precursors is preserved during the carbonization and sulfurization process. The carbonization temperature can affect the size of NiS 2 nanoparticles formed in the nanostructures. The as-obtained materials can serve as electrode materials in supercapacitors and present excellent electrochemical behavior due to their good electrical conductivity and unique structures. [Display omitted] • Controlled synthesis of three-dimensional NiS 2 /graphene nanostructures. • Carbonization temperature affects the particle size of NiS 2 in the nanostructure. • NiS 2 /graphene nanostructures present superior electrochemical performance. [ABSTRACT FROM AUTHOR]

A simple method by using Ni-based salts as the catalysts has been successfully developed to prepare porous carbons. The results show that Ni-based salts significantly affect the morphology, porous structure and graphitization degree of carbon materials. More importantly, it is found that the anions in the Ni-based salts also play important roles sor have synergistic effects for the formation of carbon materials. The obtained porous carbons can be used as electrode materials for supercapacitors and present excellent electrochemical behaviors. It is found that mesopores can accelerate the ion diffusion, ensuring full utilization of micropores and increasing gravimetric capacitance. Furthermore, a rational proportion between mesopores and micropores is also important for improving the electrochemical performance of porous carbons. In addition, the better electron conductivity arising from higher graphitization degree is also beneficial for the improvement of electrochemical behaviors. Image 1 • Ni-based salts affect the morphology, porous structure and graphitization degree. • Anions play important roles in the formation of carbon materials. • Rational proportion of mesopores and micropores improve electrochemical behaviors. [ABSTRACT FROM AUTHOR]