Triboelectric nanogenerators with enhanced output performance by surface texturing and dielectric constant control.

Double perovskite oxides Gd 0.8 Ca 0.2 BaCo 2-O 5?d have been successfully prepared by EDTA-citrate complexation process. The prepared samples were characterized by means of thermogravimetry-differential analysis, X-ray diffraction, Fourier transform infrared spectroscopy techniques. These analyses suggested that pure Gd 0.8 Ca 0.2 BaCo 2 O 5?d phase could be formed when the pH value was maintained above three and calcination temperature was higher than 850°C. The conductivity properties analyzed by means of four probes method, scanning electron microscopy and X-ray photoelectron spectroscopy indicated an improvement in conductivity with a high value of nearly 1200 S/cm, which was due to an increase in the number of small polaron hopping conduction units, Co 3? -O-Co 4? . Interestingly, the Gd 0.8-Ca 0.2 BaCo 2 O 5?d samples exhibited a semiconducting behavior through a wide range of temperature below 100°C and a metallic behavior at 100-500°C, thereby demonstrating that Gd 0.8 Ca 0.2 BaCo 2 O 5?d could meet the requirements of a smart material.

An iridium-catalyzed hydrogen transfer reaction was successfully applied in the synthesis of 2-substituted quinazolines in moderate yields starting from aldehydes or alcohols with 2-aminobenzylamines.

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Solar light responsive polymer composites which can deform their shape according to the variation in sunlight power density are prepared by incorporating the solar light photothermal fi ller of Sm 0.5 Sr 0.5 CoO 3 (SSC) into crosslinked poly[ethylene-ran -(vinyl acetate)] (EVA). Dual shape-memory effect, temperature-memory effect, and reversible bidirectional shapememory effect are all achieved in such EVA-SSC composites. Dual shape-memory effect with fi xation ratio over 99% and recovery ratio over 95% is presented, while the responsive power density is adjusted from 0.4 to 0.1 w cm −2 by simply decreasing the programming temperature from 140 to 50 °C. Furthermore, during a cyclic variation in power density from 0 to 0.3 w cm −2 and back to 0 w cm −2 in 6 min, the composite specimens show a reversible angle deformation. Finally, a sunlight-adaptive circuit switch is demonstrated using such composites, automatically turning off the LED lamp and turning on the motor fan according to the sunlight power density.

Water collection from fog has received much attention to meet the challenges of scarcity of clean drinking water in desert and arid regions. Currently, solar‐thermal technology is being used as an efficient, sustainable, and low‐cost method for water desalination to produce clean water. To collect the clean water, in recent years, most researchers have designed the structure of water collection surfaces. However, the heat released during the liquefaction process of droplets has an adverse effect on the condensation of droplets, and thus affecting the water collection efficiency. Here, in order to improve water collection efficiency, a radiative cooling layer is introduced on the back of the collection surface to dissipate the heat released during droplet liquefaction. The radiative cooling layer, consisting of poly(vinylidene fluoride‐co‐hexafluoropropene) embedded with SiO2 and CaMoO4 nanoparticles, can theoretically cool 18.1 °C below the ambient temperature in the daytime. With the addition of cooling coating on the back of the water collection surface, the water harvesting efficiency can be increased by 43–52%. The developed water harvesting device may provide a new pathway to the efficient collection of fresh water.

Four new coordination complexes, M2(Htmopa)4(H2O)4 (M = Zn2+ (1), Mn2+ (2), (M(Htmopa)2(H2O)2)n (M = Ni2+ (3), Co2+ (4)), have been synthesized by the hydrothermal reaction of Htmopa (Htmopa = 2,3,6,7-tetramethoxyphenanthrene-9-carboxylic acid) with different transition metals at a suitable temperature. Single-crystal determinations revealed that 1 and 2 are isostructural and possess a dinuclear subunit, each connected into 3D networks by hydrogen bonds and C-H...pi interactions. 3 and 4 are also isostructural: the metal ions are bridged through water molecules and carboxylate oxygen atoms to form 1D wavelike double chains, and these double chains are further extended to a 3D network via hydrogen bonds and C-H...pi interactions. The photoluminescent properties of the free Htmopa ligand and its complexes have been studied in the solid state at room temperature. Both Htmopa and 1 exhibit strong blue emissions. Magnetic susceptibility measurements indicate that 2 and 3 exhibit antiferromagnetic coupling, whereas 4 shows a ferromagnetic coupling and exhibits a single-ion behavior of the Co II ion at a higher temperature range.