Hybrid nano-architectures with high electrochemical performance for supercapacitors have been designed by growing hierarchical ZnO NRs@CuS@PEDOT@MnO2 core@shell heterostructured nanorod arrays on ITO/glass substrates. This hybrid nano-structured electrode exhibits excellent electrochemical performance, with a high specific areal capacitance of 19.85 mF cm−2, good rate capability, cycling stability and diffused coloured transparency.
Silver nanoparticles (NPs) on glass substrates were obtained by a solid-state thermal dewetting (SSD) process using vacuum-evaporated-silver precursor layers. An exhaustive investigation of the morphological, structural, and surface chemistry properties by systematically controlling the precursor film thickness, annealing temperature, and time was conducted. Thin silver films with thicknesses of 40 and 80 nm were deposited and annealed in air by applying a combined heat-up+constant temperature–time program. Temperatures from 300 to 500 °C and times from 0 to 50 min were assayed. SSD promoted the morphological modification of the films, leading to the Ag NPs having a discrete structure. The size, shape, surface density, and inter-nanoparticle distance of the nanoparticles depended on the initial film thickness, annealing temperature, and time, exhibiting a cubic silver structure with a (111) preferred crystallographic orientation. The prepared NPs were found to be highly enriched in the Ag{111}/Ag{110}/Ag{100} equilibrium facets. SSD not only promotes NP formation but also promotes the partial oxidation from Ag to AgO at the surface level. AgO was detected on the surface around the nanoparticles synthesized at 500 °C. Overall, a broad framework has been established that connects process factors to distinguish resultant Ag NP features in order to develop unique silver nanoparticles for specific applications.
27 May 2016 in Journal of the Electrochemical Society
The effect of both a RF sputtered Al-doped ZnO (AZO) thin film seed layer onto a FTO/glass substrate and its growth time onto the morphological, structural and optical properties of the resulting electrochemically grown ZnO nanorod arrays (NRAs) have been studied. ZnO NRs grown onto the different AZO seed layers exhibit smaller mean diameter and length than those grown onto a bare FTO/glass substrate, but ZnO NR density presents an opposite behavior, by using an AZO seed layer ZnO nanorod density can be increased by a factor of six. ZnO nanorods are highly crystalline with a wurtzite hexagonal structure and with a preferential growth perpendicular to the substrate. The c-axis of most of the ZnO NRs grown onto an AZO seed layer is aligned within ±6° from the substrate surface normal. Both NRAs mean length and density increases light scattering, without greatly affecting the spectra shape. The diffuse reflectance intensity is more sensitive to NR density variations than to length or diameter variations. NR diameter affects directly the shape of these diffuse reflectance spectra: they red-shifts and broadens when NR mean diameter increases. A small influence in the UV edge due to size quantization may be also present.
11 February 2010 in Journal of Materials Chemistry
In this work, we describe for the first time a high-energy and transparent thin film electrode made from nanosized LiFeO2 grown on an indium tin oxide (ITO) substrate and in situ mixed with submicronic grains of Ag homogeneously distributed to improve the conductivity. An accurate description of its texture and structure was accomplished by combining various techniques such as XPS, SEM, TEM, EDX and AFM. The electrode has the ability to deliver capacity values above 160 Ah kg−1 upon extensive cycling with capacity retention near to 98%, an average voltage of 3.0 V vs. Li+ /Li and a specific energy close to 410 W h kg−1 as a result.