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Using praseodymium nitrate, cobalt acetate and citric acid as main raw materials, the PrCoO3 photocatalyst was prepared by sol-gel method. The PrCoO3 samples were characterized by thermogravimetry and differential scanning calorimetry (TG-DSC), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR). The photocatalytic activity of PrCoO3 was tested by simulating polluted water with 10 mg/L methyl orange solution under ultraviolet light irradiation. The results show that pure PrCoO3 can be prepared by calcination in the range of 600 to 900 °C. The average particle size of PrCoO3 is about 30 μm. The photocatalytic performance of PrCoO3 is the best under the conditions of 700 °C calcination and ultraviolet light irradiation for 120 min, and the degradation rate of methyl orange (10 mg/L) can reach 98%. The PrCoO3 samples are consistent with first-order kinetics for the degradation of methyl orange. And the apparent rate constants is k = 0.0346 min−1. PrCoO3 sample shows good ultraviolet light photocatalytic activity and has a broad application prospect in the field of photocatalysis. [ABSTRACT FROM AUTHOR]

Using Pr(NO3)3·6H2O, NH4VO3 and C6H8O7·H2O as main raw materials, PrVO4 was successfully prepared by sol-gel method. The structure and morphology of samples were characterized by thermogravimetry and differential scanning calorimetry (TG-DSC), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and UV-visible diffuse reflectance spectroscopy (DRS). The effects of different synthesis temperature and light time on the photocatalytic activity of PrVO4 samples were investigated using methyl orange solution as simulated sewage. The results show that PrVO4 of pure tetragonal zircon structure can be prepared at calcination temperature of 600 °C ∼900 °C. PrVO4 particles were relatively uniform with average grain size of 1 ∼ 3 μm. The photocatalytic activity of sample prepared at 800 °C was the best. After UV irradiation for 150 min, the degradation rate of 10 mg/L methyl orange is nearly 100% in presence of PrVO4 sample prepared at 800 °C. The PrVO4 showed excellent photocatalytic activity for degradation of methyl orange. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is a transition metal that is highly toxic in biological systems. Anthropogenic emissions of Cd have increased biogeochemical cycling and the amount of Cd in the biosphere. Here we studied the utility of a bacterial Cd-binding protein, CadR, for the remediation of Cd contamination. CadR was successfully targeted to chloroplasts using a constitutive Cauliflower mosaic virus (CaMV) 35S promoter or a shoot-specific Chl a/b-binding protein 2 gene (CAB2) promoter and an RbcS (small subunit of the Rubisco complex) transit peptide. Under short-term (2 d) exposure to Cd, the cadR transgenic plants showed up to a 2.9-fold Cd accumulation in roots compared with untransformed plants. Under medium term (7 d) exposure to Cd, the concentrations of Cd in leaves began to increase but there were no differences between the wild type and the cadR transgenic plants. Under long-term (16 d) exposure to Cd, the cadR transgenic plants accumulated greater amounts of Cd in leaves than the untransformed plants. Total Cd accumulation (µg per plant) in shoots and roots of the plants expressing cadR were significantly higher (up to 3.5-fold in shoots and 5.2-fold in roots) than those of the untransformed plants. We also found that targeting CadR to chloroplasts facilitated chloroplastic metal homeostasis and Chl b accumulation. Our results demonstrate that manipulating chelating capacity in chloroplasts or in the cytoplasm may be effective in modifying both the accumulation of and resistance to Cd., (© The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.)