The solid-state transformation phenomena of spinodal decomposition and nucleation and growth are presented as tools to create nanostructured thermoelectric materials with very low thermal conductivity and greatly enhanced figure of merit. The systems (PbTe)(1-x)(PbS)(x) and (Pb(0.95)Sn(0.05)Te)(1-x)(PbS)(x) are not solid solutions but phase separate into PbTe-rich and PbS-rich regions to produce coherent nanoscale heterogeneities that severely depress the lattice thermal conductivity. For x > approximately 0.03 the materials are ordered on three submicrometer length scales. Transmission electron microscopy reveals both spinodal decomposition and nucleation and growth phenomena the relative magnitude of which varies with x. We show that the (Pb(0.95)Sn(0.05)Te)(1-x)(PbS)(x) system, despite its nanostructured nature, maintains a high electron mobility (>100 cm(2)/V x s at 700 K). At x approximately 0.08 the material achieves a very low room-temperature lattice thermal conductivity of approximately 0.4 W/m x K. This value is only 28% of the PbTe lattice thermal conductivity at room temperature. The inhibition of heat flow in this system is caused by nanostructure-induced acoustic impedance mismatch between the PbTe-rich and PbS-rich regions. As a result the thermoelectric properties of (Pb(0.95)Sn(0.05)Te)(1-x)(PbS)(x) at x = 0.04, 0.08, and 0.16 were found to be superior to those of PbTe by almost a factor of 2. The relative importance of the two observed modes of nanostructuring, spinodal decomposition and nucleation and growth, in suppressing the thermal conductivity was assessed in this work, and we can conclude that the latter mode seems more effective in doing so. The promise of such a system for high efficiency is highlighted by a ZT approximately 1.50 at 642 K for x approximately 0.08.

The development of efficient and low energyconsumption catalysts for CO 2 conversion is desired, yet remains ag reat challenge.H erein, ac lass of novel hollow porous carbons (HPC), featuring well dispersed dopants of nitrogen and single Zn atoms,h ave been fabricated, based on the templated growth of ah ollow metal-organic framework precursor,f ollowed by pyrolysis.T he optimizedH PC-800 achieves efficient catalytic CO 2 cycloaddition with epoxides, under light irradiation, at ambient temperature,b yt aking advantage of an ultrahigh loading of (11.3 wt %) single-atom Zn and uniform Na ctive sites,h igh-efficiency photothermal conversion as well as the hierarchicalpores in the carbon shell. As far as we know,this is the first report on the integration of the photothermal effect of carbon-based materials with single metal atoms for catalytic CO 2 fixation.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

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The development of zeolite-like structures with extra-large pores (>12-membered rings, 12R) has been sporadic and is currently at 30R. In general, templating via molecules leads to crystalline frameworks, whereas the use of organized assemblies that permit much larger pores produces noncrystalline frameworks. Synthetic methods that generate crystallinity from both discrete templates and organized assemblies represent a viable design strategy for developing crystalline porous inorganic frameworks spanning the micro and meso regimes. We show that by integrating templating mechanisms for both zeolites and mesoporous silica in a single system, the channel size for gallium zincophosphites can be systematically tuned from 24R and 28R to 40R, 48R, 56R, 64R, and 72R. Although the materials have low thermal stability and retain their templating agents, single-activator doping of Mn(2+) can create white-light photoluminescence.

A nanoporous zinc gallophosphate framework, NTHU-4, possessing 14-ring channels, disordered rims, and two luminant analogues, NTHU-4Y and NTHU-4W, has been synthesized and characterized; NTHU-4Y is an intrinsic yellow phosphor, while NTHU-4W is a white phosphor. The unique tetrahedral framework can be excited by wavelengths longer than 254 nm to give intense yellow-to-white luminescence. Subtle changes in disorderliness were observed to be related to the distinct photoluminescence property.

A UiO-66 analog was synthesized in 100 s using water-assisted grinding. The linker solubility suggested that tetrafluorobenzene-1,4-dicarboxylic acid was the best linker. Zr-metal-organic framework nanocrystals displayed good topologies and hydrophobicities, and high water/thermal stabilities. The less amorphous complex led to higher porosities and pore volumes with a 60 min grinding time.

Six new calcium metal−organic frameworks [Ca(BDC)(DMF)(H2O)] (1), [Ca(ABDC)(DMF)] (2), [Ca3(BTC)2(DMF)2(H2O)2]·3H2O (3), [Ca(H2dhtp)(DMF)] (4), [Ca(H2dhtp)(DMF)2] (5), and one modification of [Ca(H2dhtp)2(H2O)2] (6), (DMF = N,N-dimethylformamide; BDC = 1,4-benzenedicarboxylate anion; ABDC = 2-aminobenzene-1,4-dicarboxylate anion; BTC = 1,3,5-benzenetricarboxylate anion; H2dhtp = 2,5-dihydroxyterephthalate anion) were synthesized from calcium ions and aromatic carboxylic acids by solvothermal reactions and microwave-assisted solvothermal reactions. The single crystal structure analysis showed that all complexes display three-dimensional structures containing various inorganic motifs with helical or straight one-dimensional inorganic chains (1−3), pentagonal bipyramidal dimers (4 and 6), or discrete octahedra (5) connected through organic linkers and forming DMF- or water-coordinated neutral frameworks. It is also interesting that compounds 1−5 undergo dissolution/reorganization reactions comprising a break and reformation of the Ca−O bond and leading to destruction/construction structural transformations. Compounds 1−5 were further characterized by thermal gravimetric analysis, powder X-ray diffraction, UV−vis, infrared, and PL spectroscopy.

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