NP [CGG-Fluorescein]

We use gas phase deposition of well-defined nanoparticles (NPs) to fabricate closely-spaced Pd NP arrays on flexible membranes prepatterned with interdigital electrodes (IDEs). The evolution of the morphology and electron conductance of the NP arrays during deposition is analyzed. The growth of two-dimensional percolation clusters of interconnected NPs, which correlate with the percolation pathway for electron conduction in the NP deposits, is demonstrated. The percolative nature of the NP arrays permits us to finely control the percolation geometries and conductance of the NP film by controlling the NP deposition time so as to realize a precise and reproducible fabrication of sensing materials. Electron transport measurements reveal that the electrical conductance of the NP films is dominated by electron tunneling or hopping across the NP percolating networks. Based on the percolative and quantum tunneling nature, the closely-spaced Pd NP films on PET membranes are used as flexible strain sensors. The sensor demonstrates an excellent response ability to distinguish tiny deformations down to 5x10(-4) strain and a high sensitivity with a large gauge factor of 200 up to 4% applied strain.

Solar photocatalytic treatment of greywater, collected from a residential apartment, was performed in the study using nitrogen-doped TiO2 (NP-TiO2) coated on gravels. XRD pattern displayed dominance of the anatase phase of NP-TiO2. Morphological analysis by SEM images indicated the improved porous structure of NP-TiO2 with an average particle size of 109.11 nm with a size range of 91-120 nm. Elemental analysis confirmed the formation of NP-TiO2 by the doping of N into the P-25 structure, and UV-visible spectroscopy results showed improvement in visible light absorption. The efficacy of greywater treatment was evaluated in terms of the degradation of organics, nutrients, surfactants and benzophenone (BP). Solar photocatalytic degradation resulted in significant removal of organics (total organic carbon, TOC removal of 93.7%), with a degradation rate of 0.393 h(-1). A maximum of 50% TKN removal efficiency was achieved with photocatalytic oxidation to nitrate. Furthermore, the nitrate removal efficiency of 43% was observed due to the photocatalytic reduction. The maximum removal efficiency of phosphate, surfactant and BP was 55, 75, and 98.5%, respectively. Besides, toxicity in terms of bioluminescence inhibition (for 30 min incubation) showed a reduction from 13.6 to 4% for the treated greywater. The non-specific hydroxyl radical attack, demethylation, and bond cleavage between the carbonyl group and benzene ring carrying hydroxyl and methoxy groups were the dominant mechanism of BP degradation. The catalyst reusability test showed similar to 0.7% and similar to 1.5% decrease in TOC and BP removal efficiencies, respectively, after three consecutive cycles.