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Thermoelectric materials, which can directly convert thermal energy into electricity, play an important role in waste heat recovery. Sb2Si2Te6 is a promising medium-temperature thermoelectric material for power generation. However, its application is restricted by the relatively low power factor (PF) and the decompostion at high temperature. Herein, we successfully improved the power factor of Sb2Si2Te6 by doping with germanium (Ge). Benefiting from the optimized carrier concentration, the power factor of Sb2Si1−xGexTe6 remains higher than 1100 μW m−1 K−2 from 473 K to 773 K and the highest zT value reaches 1.0 at 773 K. Furthermore, the power generation performance of a single-pair thermoelectric module, consisting of Sb2Si1.94Ge0.06Te6 and Mg3.2Sb1.5Bi0.49Te0.01, is evaluated by three-dimensional numerical simulation. The simulated conversion efficiency is as high as 13% at a temperature difference of 500 K, and the power density can reach up to 3 W cm−2. Our results demonstrate that Ge doping can effectively modify the thermoelectric properties of Sb2Si2Te6 and improve its power generation performance, paving the way for realistic applications in the medium-temperature region. [ABSTRACT FROM AUTHOR]

Rice may absorb Cadmium (Cd) from the air through its leaves. The process of Cd foliar absorption, accumulation, and redistribution is yet unknown, nevertheless. In this study, the process of Cd absorption from rice leaves and its accumulation and redistribution during all stages of the rice plant's growth were examined. Stable isotope ( 108 Cd) tracing was used to investigate the distribution of Cd absorbed by leaves in different organs, and a short-term targeted leaf feeding experiment was used to explore the transport pathways and distribution of leaf-absorbed Cd in rice. Leaf-absorbed Cd could be transported to other parts of rice over long distances. Most of it was retained in the leaves and husks, a small part in the grains, and it was rarely distributed to the roots. The contribution of leaf-absorbed Cd to total Cd accumulation was the maximum in the husks (48.96 %-88.24 %), followed by the shoots (23.13 %-44.11 %), grains (22.13 %-24.15 %), and roots (4.57 %-15.21 %). Though the Cd accumulated in grains was predominately derived from root uptake compared with foliar uptake, foliar uptake was not negligible and the contribution rate was >20 %. Additionally, with the short-term fluorescent labeling experiment of leaf-targeted feeding, strong Cd fluorescence signals were observed in the phloem of both labeled and upper leaves, indicating that the Cd retransport process between the above- and belowground parts of rice was very active. Our findings preliminarily revealed the pathway and physiological mechanism of Cd absorption and reuse in rice leaves and provided theoretical support for the formulation of field management policies and control of Cd accumulation in rice. ENVIRONMENTAL IMPLICATION: Previous research indicates that the absorption of soil Cd by rice roots is the main mechanism responsible for Cd accumulation in plants. Therefore, many scholars have proposed various deterrent measures for overcoming soil pollution but neglected the role of leaves in absorbing heavy metals, e.g., Cd, from the atmosphere. Moreover, Cd foliar uptake, accumulation, and redistribution processes are still unclear. Our findings preliminarily revealed the physiological mechanism and pathway of Cd absorption and reuse in rice leaves and provided theoretical support for the formulation of field management policies and control of Cd accumulation in rice., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest. This manuscript has not been published or presented elsewhere in part or in entirety and is not under consideration by another journal. We have read and understood your journal's policies, and we believe that neither the manuscript nor the study violates any of these. There are no conflicts of interest to declare., (Copyright © 2024. Published by Elsevier B.V.)