Effect of Accelerated Thermal Ageing on the Selective Solar Thermal Harvesting Properties of Multiwall Carbon Nanotube/Nickel Oxide Nanocomposite Coatings

Abstract

Varying amounts of dispersed multiwalled carbon nanotubes in NiO have been used to develop composites that absorb the solar energy very well but lose very little through emission. Determination of absorptance,αsol, and emissivity,εther, from such selective solar absorbers shows that the optimum efficiency of 71% can be attained when about 10 mg of MWCNTs are composited with NiO. One such absorber was subjected to thermal ageing tests. The performance criterion (PC) limit for passing the test when simulated for 25 years is(−Δα+0.25Δε)≤0.05. It was found that the typical absorber had a PC value of −0.01. This value is much better than the passing limit. Raman spectra of the typical absorber before and after the thermal ageing test showed a reduced intensity in the D and G bands of disordered and graphitic carbon, respectively but an enhancement of the NiO bands indicating loss of carbon atoms due to thermal ageing tests. Simple equations are derived determining the proportion of carbon atoms that are lost and the proportion of carbon atoms that remains in the absorber; both of these are in agreement with the original carbon composition before the thermal ageing test. It is reported that the typical absorber will retain 63% of the carbon after 25 years.

Ni(II)-Dimeric Complex-Derived Nitrogen-Doped Graphitized Carbon-Encapsulated Nickel Nanoparticles: Efficient Trifunctional Electrocatalyst for Oxygen Reduction Reaction, Oxygen Evolution Reaction, and Hydrogen Evolution Reaction

“…Furthermore, XPS studies confirm our observations where we could evaluate the atomic percentage of nitrogen in annealed samples. The peaks at 520 and 1100 cm –1 in Ni-NC700, Ni-NC800, and Ni-NC900 correspond to surface oxidation of Ni into NiO. , This clearly indicates along with Ni nanoparticles the presence of nickel oxide nanoparticles (Figure b).…”

Review of nanomaterial aging and transformations through the life cycle of nano-enhanced products

“…It was found, for instance, that Au NPs deposited on Indium Tin Oxide electrodes (Kang et al, 2010) and Pt-Cu alloy NP electrocatalyst precursors (Koh and Strasser, 2010) decrease their electrocatalytic activities, even at ambient temperature. In the case of solar energy, thermal absorbers made of MWCNT/NiO composites, exposed for 200 h at 250°C, simulating a 25 year aging pattern under normal use conditions, induced a slight decrease in reflectance, correlated with decreases of C/Ni and of particle size (Roro et al, 2012). Soot oxidation can also be promoted via catalytic converters.…”

Synthesis and characterisation of nickel oxide nanofibre webs with alcohol sensing characteristics

“…Also, it is antiferromagnetic in nature. As functional ceramics, NiO based materials are widely used in sensors, 36 electrochromic devices, 37 solar-energy absorbers, 38,39 lithium-ion batteries, 40 supercapacitors, 41 heterogeneous catalysts, 42 hydrogen evolution 43 and as magnetic materials. 44,45 In this study, nanocrystalline NiO nanobres were fabricated by calcining electrospun poly(2-ethyl-2-oxazoline) (PEtOx)/ nickel(II) acetate tetrahydrate (NATH) nanobres.…”