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It has been shown previously that the thermoelectric properties of the Zintl phase compound, YbZn2Sb2 can be finely tuned via substitution at the cationic Yb-site. Here we report the results of the investigation of isoelectronic substitution of Zn by Mn in the anionic (Zn2Sb2)2− framework. The p-type YbZn2−xMnxSb2 (0.0⩽x⩽0.4) samples have been synthesized via a solid-state reaction followed by suitable cooling, annealing, grounding, and hot-pressing densification processes. In samples with x=0.0, 0.05, 0.10, 0.15, 0.2, 0.3, and 0.4, the electrical conductivity, Seebeck coefficient, and thermal conductivity measurements have been performed as a function of temperature from 300to750K. It is found that the Mn substitution effectively lowers the thermal conductivity for all samples, while it significantly increases the power factor for x⩽0.15. As a result, a dimensionless figure of merit ZT of ∼0.61–0.65 has been attained at 726K for x=0.05–0.15 as compared to the ZT of ∼0.48 in the unsubstituted YbZn2Sb2.

Self-assembled and well-aligned nanowires (NWs) of poly­(3-hexyl­thiophenes) (P3HT) embedded within insulating polystyrene (PS) matrix were found to have a high field-effect carrier mobility. We demonstrate that solution shear coating of P3HT-NWs/PS nanocomposites is an effective strategy in aligning P3HT NWs in the presence of PS and has a significant impact on the molecular order, morphology, and consequently charge transport. Shear-coated P3HT-NWs/PS nanocomposites consistently exhibited higher carrier mobilities compared to P3HT NWs or pristine P3HT/PS films by up to 10.2-fold. P3HT-NWs/PS nanocomposites containing only 3 wt % P3HT exhibit a mobility of ∼0.053 cm2 V–1 s–1, which is comparable to that of the 30 wt % P3HT (∼0.064 cm2 V–1 s–1) and even higher than that of 100 wt % P3HT (∼0.024 cm2 V–1 s–1).

Indium-filled CoSb3 skutterudites have been shown previously to have promising thermoelectric properties but the thermal conductivity still remains somewhat high. In order to further decrease the thermal conductivity, the double-filling approach has been adopted using ytterbium, in conjunction with indium, due to its heavy mass and small size. The In0.1YbyCo4Sb12 (y=0.00, 0.05, 0.10, and 0.20) samples have been prepared by a melting method and subsequently characterized by means of electron microscopy, electrical resistivity, Seebeck coefficient, thermal conductivity, and Hall coefficient measurements. The results show that the ytterbium filling effectively decreases the thermal conductivity without degrading the power factor, resulting in an enhancement of the dimensionless figure of merit ZT. A state-of-the-art ZT value of 0.97 is attained in In0.1Yb0.1Co4Sb12 at 750 K.

Electrocatalytic water splitting is an emerging technique to produce sustainable hydrogen energy. However, it is still challengeable to fabricate a stable, efficient, and cost-effective electrocatalyst that can overcome the sluggish reaction kinetics of water electrolysis. In order to reduce the energy barrier, for the first time, metal−organic framework (MOF)-derived nickel (Ni) and nickel sulfide (NiS) heteronanoparticleembedded semi-MOFs are prepared by a partial sulfurization strategy. These semi-MOF electrocatalysts inherit the advantages associated with MOF architecture and nanoparticles, unlike the traditional OER catalysts such as pristine MOFs or completely pyrolyzed MOFs. Due to the unique nanoarchitecture fabricated by Ni/NiS heteronanoparticles within semi-MOF nanosheets and a carbon nanotube (CNT) network (Ni-M@C-130), it displays exceptional bifunctional activity over the other transition metalbased electrocatalysts ever reported. It requires very small overpotentials for both oxygen evolution reaction (OER; η 10 = 244 mV) and hydrogen evolution reaction (HER; η 10 = 123 mV), with low Tafel slopes of 47.2 and 50.8 mV/dec, respectively. Furthermore, it exhibits overpotential as low as 1.565 V (η 10 ) on nickel foam (1 mg/cm 2 ) substrates for overall water splitting. The outstanding catalytic performance of Ni-M@C-130 is attributed to the combined benefits of MOF nanosheets, synergistic interactions, and improved electrical conductivity and mechanical stability. This study describes the advantages of partial sulfurization of CNT-integrated MOFs in attaining electrochemically active heteronanoparticles within MOF nanosheets to accomplish improved bifunctional activity.

Strategic design and fabrication of a highly efficient and costeffective bifunctional electrocatalyst is of great significance in water electrolysis in order to produce sustainable hydrogen fuel in a large scale. However, it is still challenging to develop a stable, inexpensive, and efficient bifunctional electrocatalyst that can overcome the sluggish oxygen evolution kinetics in water electrolysis. To address the aforementioned concerns, a metal−organic framework-derived Fe-doped Ni 3 Fe/NiFe 2 O 4 heterostructural nanoparticle-embedded carbon nanotube (CNT) matrix (Fe(0.

Mo 3 Sb 7 − x Te x is a high temperature thermoelectric material, reported to reach figure of merit (ZT)=0.8 at 1023 K. Various p-type samples of NiyMo3Sb7−xTex were prepared with y≤0.1 and 1.5≤x≤1.7 via high temperature reactions at 993 K. Adding transition metal atoms into the empty cube formed by Sb atoms significantly alters the band structure and thus the thermoelectric properties. Electronic band structure calculations indicate that adding Ni slightly increases the charge carrier concentration, while higher Te content causes a decrease. Thermoelectric properties were determined on pellets densified via hot pressing at 993 K. Seebeck as well as electrical and thermal conductivity measurements were performed up to 1023 K. The highest ZT value thus far was obtained from a sample of nominal composition Ni0.06Mo3Sb5.4Te1.6, which amounts to 0.93 at 1023 K.

Catenated poly­(ε-caprolatone) (PCL) and poly­(l-lactide) (PLA) were synthesized by a ring-expansion strategy based on a catenated tin initiator. Catenated PCLs with different degrees of polymerization (DP n ) were obtained by modifying the feed ratios of monomer to initiator, and subsequent decomplexation rendered the copper-free catenated PCL. Both the Cu­(I)-templated catenated PCL and Cu­(I)-free catenated PCL were characterized by UV–vis, 1H NMR, FT-IR, and GPC analyses. The comparative GPC analyses of catenated polymers and their linear analogues were also performed, which revealed a reduced hydrodynamic diameter for the catenated polymers. The crystallinity of the catenated PCL compared to that of linear PCL was also studied by DSC and WAXS, and the Cu­(I)-free catenated PCL exhibited a lower degree of crystallinity but larger crystallite size.