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Environmental pollution, in particular, the wastewater from the textile and dyeing production process is causing serious issues for the ecosystem and humans. It has been well-demonstrated that zero-valent iron nanoparticles (nZVI) are one of the most promising materials in the treatment of environmental pollutants. In this work, the Cleistocalyx operculatus leaf extract was employed as a green reductant for the synthesis of the nZVIs nanoparticles from iron ions precursor. Notably, a microfluidic device was also used as micro-reactor for the synthesis process of the nanoparticles, making it easy to control and optimise the morphologies and sizes of nZVI. The morphology and crystallinity of nZVI were characterised by scanning electron microscopy (SEM) and x-ray diffraction (XRD), respectively. The nZVIs prepared in a microfluidic reactor using Cleistocalyx operculatus leaf extract as reductant were in plate-like structure with the thickness of around 5 nm and the diameter in range of hundred nanometers. The removal efficiency of Rhodamin B (RhB) dye by the prepared nZVI was determined by ultraviolet-visible (UV–vis) spectroscopy. The results showed that the nZVI revealed high removal performance toward RhB with removal efficiency of higher than 90% after 30 min of treatment. The effects of dye’s concentration, time, and pH solution on the treatment performance of RhB were also studied.

The control of the aging conditions for the aluminium alloys has been considered as an effective strategy to improve the properties of the alloy, especially in enhancement of the corrosion resistance. In this study, a detailed investigation of the effect of one-stage (T6) and two-stage (T76x) aging temper on mechanical properties, exfoliation and intergranular corrosion behaviours of 7075 Al–Zn–Mg–Cu alloy was implemented. Microstructures of the aged alloys were observed by optical microscopy and scanning electron microscopy (SEM), exfoliation and intergranular corrosion behaviours were investigated according to ASTM G34-2001 and ASTM G110-1992, respectively; the mechanical properties of the aged alloys were determined followed the standard methods. The microstructures of the sample aged with the T6 temper showed the finer particle size of precipitates than that of obtained from T76x tempers. Additionally, while the T6-aged sample revealed no appearance of the Precipitate Free Zones (PFZ), the PFZ with 40–50 nm in width was observed in the alloys treated with T76x tempers. The mechanical properties of the sample aged with T76x temper were negligibly reduced comparing to that of obtained with T6 temper, however, the exfoliation and intergranular corrosion behaviours were significantly improved by using two-stage aging conditions. The mechanism in enhancement of the corrosion resistance of the alloys treated with T76x temper over T6 temper was also discussed.

The solar spectrum consists of 8% UV radiation, while 45% of solar energy is from visible light. It is therefore desirable to fabricate a hybrid material which is able to harvest energy from a wide range of photons from the sun for applications such as solar cells, photovoltaics, and photocatalysis. In this study we report on the fabrication of a TiO 2 @porphyrin hybrid material by surfactant-assisted co-assembly of monomeric porphyrin molecules with TiO 2 nanoparticles. The obtained TiO 2 @porphyrin composite shows excellent integration of TiO 2 particles with diameters of 15-30 nm into aggregated porphyrin nanofibers, which have a width of 70-90 nm and are several μm long. SEM, XPS, XRD, FTIR, UV-Vis and fluorescence spectroscopy were employed to characterize the TiO 2 @TCPP hybrid material. This material exhibits efficient photocatalytic performance under simulated sunlight, due to synergistic photocatalytic activities of the porphyrin aggregates in visible light and TiO 2 particles in the UV region. A plausible mechanism for photocatalytic degradation is also proposed and discussed.