Facile solution synthesis of Cu2O-CuO-Cu.OH)(2) hierarchical nanostructures for effective catalytic ozone decomposition

Various Cu-based composites for catalytic ozone decomposition have been synthesized by the reduction of Cu2+ using NH2OH<bold>HCl in an aqueous solution without the addition of any extra etching agent</bold>. A Cu2O-CuO heterogeneous composite with many nanometer-sized CuO nanoplates distributed on the Cu2O surface as well as Cu(OH)(2) nanowires was fabricated, and the structural evolution process was explored. The mechanism for the structure's formation can be attributed to the synergistic reaction of oxidation etching and acidic etching. It was found that the surface morphology and chemical composition of the nanostructures play important roles in catalyzing ozone decomposition. The Cu2O-CuO-Cu(OH)(2) hierarchical nanostructure exhibits a 100% ozone (20 ppm O-3 per air) decomposition efficiency at room temperature after 30 h of continuous operation, showing high stability. In addition, the hierarchical nanostructure also shows high moisture resistance, and the ozone conversion can still be above 80% at high relative humidity levels (ca. 90%) after a 16 h test. The excellent performance can be attributed to the delocalized holes speculated by EPR spectroscopy, which may facilitate the necessary electron transfer between intermediate oxygen anions and the catalytic surface

Gram-scale synthesis of ultra-fine Cu2O for highly efficient ozone decomposition

Nowadays, it is necessary and challenging to prepare Cu2O in a large scale for various applications such as catalysis due to its excellent properties. Here, gram-scale Cu2O with nm size is successfully prepared using a simple liquid-phase reduction method at 25 degrees C. The amount of NaOH is found to be the key factor to determine the particle size of Cu2O by modifying the complexation and reduction reactions. The obtained ultra-fine Cu2O exhibits high performance of >95% efficiency for removing high-concentration (3000 ppm) ozone at 25 degrees C and even at a high relative humidity (RH) of 90% for more than 8 h. Furthermore, the Cu2O nanoparticles are coated onto an aluminium honeycomb substrate to form a monolithic catalyst, which shows high ozone removal efficiency of >99% in dry air and >97% in 90% RH for >10 h at a space velocity of 8000 h(-1). The high performance could be attributed to the enhanced release of the ozone decomposition intermediate by the small size of Cu2O, as verified by O-2 temperature-programmed desorption and X-ray photoelectron spectroscopy. All these results show the industrial promise of the large scale synthesis of ultrafine Cu2O applicable for high-performance ozone removal

Dolichol Biosynthesis and Its Effects on the Unfolded Protein Response and Abiotic Stress Resistance in Arabidopsis[W][OA]

Dolichols are long-chain unsaturated polyisoprenoids with multiple cellular functions, such as serving as lipid carriers of sugars used for protein glycosylation, which affects protein trafficking in the endoplasmic reticulum. The biological functions of dolichols in plants are largely unknown. We isolated an Arabidopsis thaliana mutant, lew1 (for leaf wilting1), that showed a leaf-wilting phenotype under normal growth conditions. LEW1 encoded a cis-prenyltransferase, which when expressed in Escherichia coli catalyzed the formation of dolichol with a chain length around C80 in an in vitro assay. The lew1 mutation reduced the total plant content of main dolichols by ∼85% and caused protein glycosylation defects. The mutation also impaired plasma membrane integrity, causing electrolyte leakage, lower turgor, reduced stomatal conductance, and increased drought resistance. Interestingly, drought stress in the lew1 mutant induced higher expression of the unfolded protein response pathway genes BINDING PROTEIN and BASIC DOMAIN/LEUCINE ZIPPER60 as well as earlier expression of the stress-responsive genes RD29A and COR47. The lew1 mutant was more sensitive to dark treatment, but this dark sensitivity was suppressed by drought treatment. Our data suggest that LEW1 catalyzes dolichol biosynthesis and that dolichol is important for plant responses to endoplasmic reticulum stress, drought, and dark-induced senescence in Arabidopsis

Facile synthesis of In2S3/UiO-66 composite with enhanced adsorption performance and photocatalytic activity for the removal of tetracycline under visible light irradiation

In this study, a series of In2S3/UiO-66 composites were fabricated through a one-step solvothermal method for the first time. The diffraction peaks, composition, morphology, and chemical states of the composites were first characterized through X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope, or transmission electron microscope. Then, the performances of as-obtained In2S3/UiO-66 composites were assessed by the removal of tetracycline under 1 h dark condition and 1 h visible-light irradiation. Experimental results showed that all the In2S3/UiO-66 composites exhibited greater tetracycline removal, as compared with the two parent materials (i.e., UiO-66 and In2S3). The highest tetracycline removal was obtained by the developed In2S3/UiO-66 composite with Zr: In molar ratio of (0.37:1), labelled as ISUO-0.37, with the maximal tetracycline removal capacity of 106.3 mg/g being achieved, which was greater than that of UiO-66, In2S3, or other photocatalysts documented in the literature. The mechanism investigations revealed that compared with UiO-66 and In2S3, ISUO-0.37 had higher adsorption capability and photocatalytic performance. Although the specific surface area of ISUO-0.37 (74.57 m2/g) was lower than that of either UiO-66 (388.6 m2/g) or In2S3 (76.36 m2/g), the former possessed greater pore diameter and adsorption sites such as single bondOH, Cdouble bondO, Osingle bondCsingle bondO, Cdouble bondC, and Csingle bondH, which might be the reason for ISUO-0.37 showing the enhanced adsorption capability. The trapping experiment and electron spin resonance measurements demonstrated that radical dotO2− and h+ were the major contributors to the photo-degradation of tetracycline in this work, and more radical dotO2− and h+ were produced by ISUO-0.37, as compared with In2S3. Further investigation with the diffused spectra of reflectance showed that ISUO-0.37 had better visible light absorption than either In2S3 or UiO-66, which may be the reason for ISUO-0.37 producing more radical dotO2−. In addition, photoluminescence emission spectra confirmed that the recombination rate of photoexcited electron-hole pairs of ISUO-0.37 composite is much lower than that of In2S3, which may increase h+. It was also found that ISUO-0.37 showed excellent structural stability and recyclability.This research was financially supported by the project of National Natural Science Foundation of China (NSFC) (51779089, 51521006 and 21776066), the Natural Science Funds of Hunan Province for Distinguished Young Scholar (2018JJ1002), Science and Technology Project of Hunan Province (2018SK1010) and Huxiang youth talent plan of Hunan Province (2017RS3022)