We report an enhanced thermoelectric performance by manipulating band engineering in Mn−In codoped SnTe. It has been revealed that SnTe is a unique example achieving the synergy of band convergence and resonant state. According to band theory, band convergence favors heavy doping, while resonant state favors light doping. Following this idea, a series of Mn−In codoped SnTe samples are prepared by hot pressing. A significantly enhanced Seebeck coefficient of 116 μ V K − 1 at 300 K is observed in Sn 0.915 Mn 0.11 In 0.005 Te. By carefully tuning the band structure of the solid solution, we achieve a high ZT max of 1.15 at 823 K and an overall enhanced ZT ave of 0.62. The improved thermoelectric performance in a large temperature range leads to a competitive conversion efficiency of 10.1% with T c = 300 K and T h = 850 K, suggesting Mn−In codoped SnTe is a promising candidate for medium-temperature thermoelectric applications.

In the field of clinical diagnosis, it is important to construct a potential-resolved multiplex electrochemiluminescence (ECL) biosensor for decreasing the false-positive rate and improving the diagnostic accuracy. However, the shortage of low-potential cathodic luminophores between −1 and 0 V (vs Ag/AgCl) severely limited the development of the biosensor. Herein, we synthesized a novel luminophore N,N-bis-(3-dimethyl aminopropyl)-3,4,9,10-perylene tetracarboxylic acid diimide (PDI), which gave dual emissions at −0.25/–0.26 V with K2S2O8 as a co-reactant in aqueous solution. The ECL was assigned to excited J-type PDI dimers. Then, PDI and luminol were used as luminophores to respectively combine with graphite oxide and gold nanoparticles and form potential-resolved ECL nanoprobes. Also, this potential-resolved ECL nanoprobes were respectively functionalized by secondary antibodies (Ab2) to construct a low-potential sandwiched ECL immunosensor for tumor markers carcinoembryonic antigen (CEA) and α-fetoprotein (AFP) simultaneous determination during linear scanning potential range from −0.6 to 0.6 V. The prepared multiplex immunosensor exhibited sensitive ECL response for CEA at −0.6 V due to PDI and that for AFP at 0.6 V due to luminol, and both linear semilogarithmical ranges were from 0.1 pg to 1 ng mL–1. In addition, PDI with dual ECL peaks showed enticing prospect of built-in self-calibration for a precise quantitative and bioimaging analysis.

No abstract

α‐MgAgSb is recently discovered to be a new class of thermoelectric material near room temperature. A competitive ZT of 1.4 at 525 K is achieved in Ni‐doped α‐MgAgSb, and the measured efficiency of energy conversion reaches a record value of 8.5%, which is even higher than that of the commercially applied material bismuth telluride. On the other hand, the band structure of α‐MgAgSb is believed to be unprofitable to the power factor, owing to the less degenerate valence valleys. Here, this paper reports a systematic theoretical study on the thermoelectric properties by using the electron/phonon structure and transport calculations. Based on the careful analysis of Fermi surface, a principled scheme is presented to design band engineering in α‐MgAgSb. Following the given rules, several effective dopants are predicted. As two examples, Zn‐ and Pd‐doped α‐MgAgSb are numerically confirmed to exhibit an extraordinary ZT value of 2.0 at 575 K and a high conversion efficiency of 12.6%, owing to the effects of band convergence. This work develops an applicable scheme for the purposive design of band engineering, and the idea can be simply applied to more thermoelectric materials.

The hot deformation process enhances the textured degree of ploycrystalline SnSe, leading to better electrical conductivity and a high power factor of 10.2 μW cm−1 K−2 at 823 K.

An unconventional liquid-phase compaction method was used to prepare Sn0.97Na0.03Se thermoelectric materials, leading to high oritentation with excellent electrical properties.

No abstract

Cylindrospermopsin (CYN) is one of the most important cyanobacterial toxins frequently found in surface waters. We reported the detailed kinetics and pathways for the reaction of CYN with carbonate radicals (CO3 •–). The rate constants of neutral and deprotonated CYN with CO3 •– were found to be (1.2 ± 0.7) × 107 M–1 s–1 and (3.0 ± 0.4) × 108 M–1 s–1, respectively. The transformation products for the oxidation of CYN by CO3 •– were identified by high-resolution mass spectrometry, illustrating that the guanidine and bridged hydroxyl portions were the primary moieties attacked by CO3 •–. Thus, three transformation pathways, including cleavage of the hydroxymethyluracil moiety, hydroxylation, and oxidation of the bridged hydroxyl group, are proposed for the CO3 •– oxidation of CYN. Moreover, this study reported that dissolved organic matter (DOM) reduced the transformation rate of CYN by inhibiting the transformation of oxidation intermediates. Finally, the role of CO3 •– in CYN degradation was estimated in both sunlit surface waters and advanced oxidation processes (AOPs), demonstrating that CO3 •– played an important role in CYN attenuation under nonacidic environmentally relevant conditions. The kinetic parameters and product information obtained in this study will be of considerable interest for the application of AOPs and predicting the environmental fate of CYN.