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1. Ca-repaired BaZrO ₃ nanorods/YBa ₂ Cu ₃ O _7-x interface for enhanced pinning in YBa ₂ Cu ₃ O _7-x nanocomposites with 2-8% BaZrO ₃ doping

   https://doi.org/10.1088/1757-899X/1302/1/012013  

   Wu, Judy; Panth, Mohan; Ogunjimi, Victor; Ann_Sebastian, Mary; Zhang, Di; Haugan, Timothy; Wang, Haiyan (May 2024, IOP Conference Series: Materials Science and Engineering)

   Abstract C-axis aligned BaZrO₃(BZO) nanorods formed via strain-mediated self-assembly in BZO-doped YaBa₂Cu₃O_7-x(BZO/YBCO) nanocomposite films can provide strong pinning to the quantized magnetic vortices. While the strain initiated from the BZO/YBCO lattice mismatch plays a critical role in nucleation and evolution of the BZO nanorods, it also leads to a highly defective BZO/YBCO interface and hence reduced pinning efficiency of BZO nanorods. This work reports a recent study in probing the effect of BZO/YBCO interface on the pinning efficiency of the BZO nanorods as the interface is repaired dynamically during the BZO nanorod growth using Ca doping. Within the BZO doping range of 2-8 vol.%, significantly enhanced pinning efficiency of the BZO nanorods have been observed. A peak enhancement up to five-fold of critical current density at 9.0 T and 65-77 K has been obtained in the 6 vol.% BZO/YBCO nanocomposites after the interface repair. This result not only illustrates the critical importance of the BZO/YBCO interface in the pinning efficiency, but also provides a facile scheme to achieve such an interface to restore the pristine pinning efficiency of the BZO nanorods. 

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2. Eucalyptus grandis Response to Calcium Fertilization in Colombia

   https://doi.org/10.1093/forsci/fxab042  

   Grover, Zach S; Cook, Rachel L; Zapata, Marcela; Byron Urrego, J; Albaugh, Timothy J; Zelaya, Ariel; Ozyhar, Tomasz; Rubilar, Rafael; Carter, David R; Campoe, Otávio C (November 2021, Forest Science)

   Abstract Calcium (Ca) is a critical plant nutrient typically applied at the time of planting in intensive Eucalyptus plantations in South America. At two sites in Colombia, we examined (1) calcium source by comparing growth after application of 100 kg ha−1 elemental Ca as lime or as pelletized highly reactive calcium fertilizer (HRCF) compared to a no application control, and (2) Ca rate by applying 0, 100, 200, and 400 kg ha−1 elemental Ca as HRCF with the addition of nitrogen, phosphorus, potassium, sulfur, and boron (NPKSB). We assessed height, diameter, and volume after 12 and 24 months. There were no growth differences from Ca source at the 100 kg ha−1 rate. We found increased volume after 24 months at the “Popayan” site with 200 and 400 kg ha−1 Ca HRCF+NPKSB treatments (112 and 113 m3 ha−1, respectively) compared to control (92 m3 ha−1), a 22% increase. In contrast, volume did not differ after 24 months at the “Darien” site, ranging from 114 m3 ha−1 in the 0 kg ha−1 Ca HRCF+NPKSB treatment to 98 m3 ha−1 in the control. Differences in response are likely due to soil characteristics, such as organic matter, emphasizing the importance of identifying site-specific nutrient deficiencies. 

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3. Inorganic salts and organic matter effects on nanorod, nanowire, and nanoplate MoO ₃ aggregation, dissolution, and photocatalysis

   https://doi.org/10.1039/D0EN00708K  

   Fanourakis, Sofia K.; Peña-Bahamonde, Janire; Rodrigues, Debora F. (December 2020, Environmental Science: Nano)

   null (Ed.)

   Use of visible light photocatalytic nanomaterials in water treatment can be promising in treating contaminants. However, little research has been conducted examining the effects of more complex chemistries in the nanomaterial's performance. In this work, the effects of inorganic salts (NaCl and CaCl 2 ) and natural organic matter (NOM) such as humic acid (HA) and extracellular polymeric substances (EPS) on nanoparticle aggregation, dissolution, and ultimately on the photocatalytic properties of molybdenum trioxide (MoO 3 ), i.e. nanorods, nanowires, and nanoplates were examined. In the presence of NaCl, nanorod, nanowire, and nanoplate MoO 3 had similar critical coagulation concentrations, while the nanorods showed higher instability in CaCl 2 . Overall, the presence of inorganic salts caused high colloidal instability in the MoO 3 nanostructures in terms of aggregation behavior, but greatly aided in the reduction of MoO 3 dissolution. NOM presence decreased aggregation rates, albeit dissolution was not similarly affected in all three structures. Only the dissolution of the nanowire structures was reduced in the presence of HA or EPS. Furthermore, the photocatalytic activity of the nanowires and nanoplates was overall reduced when inorganic salts or natural organic matter were present. While the presence of natural organic matter alone did reduce photocatalytic effectiveness of the nanorod MoO 3 , the presence of salts seemed to negate the effects from the organic compounds. Furthermore, the presence of CaCl 2 resulted in a highly enhanced photocatalytic activity regardless of the presence of natural organic matter. The structural and chemical differences of the nanomaterials played a significant role in their aggregation, dissolution, and ability to photocatalytically degrade methylene blue in solution. This study demonstrates that a better understanding of water chemistry effects on nanomaterials is essential prior to their intended applications. 

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4. Heterostructures of Cu _2−x S/Cu _2−x Te plasmonic semiconductors: disappearing and reappearing LSPR with anion exchange

   https://doi.org/10.1039/D2CC01859D  

   Espinosa, Alba Roselia; Novak, Marc; Luo, Qi; Hole, Brandon; Doligon, Clarisse; Prenza Sosa, Kenya; Gray, Jennifer L.; Rossi, Daniel P.; Plass, Katherine E. (August 2022, Chemical Communications)

   Localized surface plasmon resonance (LSPR) of Cu 2− x S nanorods is quenched during the initial Cu 2− x S/Cu 2− x Te core/shell stage of anion exchange then returns as Cu 2− x Te progresses into the nanorod. Phase change within the core accounts for this behaviour illustrating the complexity emergent from anion exchange. 

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5. In situ formation of metal–organic framework derived CuO polyhedrons on carbon cloth for highly sensitive non-enzymatic glucose sensing

   https://doi.org/10.1039/c9tb01166h  

   Cheng, Siyi; Gao, Xiang; DelaCruz, Steven; Chen, Chen; Tang, Zirong; Shi, Tielin; Carraro, Carlo; Maboudian, Roya (August 2019, Journal of Materials Chemistry B)

   Metal–organic frameworks (MOFs) are considered promising templates for the fabrication of nanostructured materials with high porosities and high surface areas, which are important parameters for enhanced performance in sensing applications. Here, a facile in situ synthetic strategy to construct MOF-derived porous CuO polyhedrons on carbon cloth (CC) is reported. Uniform Cu(OH) 2 nanorods are first synthesized on carbon cloth, followed by the conversion of Cu(OH) 2 nanorods into porous CuO polyhedrons via a copper-based MOF, Cu–BTC, as the intermediate species. When evaluated as a glucose sensing electrode, the as-fabricated CuO polyhedrons/CC composite exhibits a high sensitivity of 13 575 μA mM −1 cm −2 with a fast response time ( t 90 ) of 2.3 s and a low detection limit of 0.46 μM. This work exemplifies the rational fabrication of porous nanostructures on conductive substrates for enhanced performance in glucose detection. 

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