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This study focuses on the effect of Cu doping on the thermoelectric properties of BiSbTe3 (BST) alloys. Firstly, we successfully prepared high-quality BST alloys using the KCl solvent method and selected the most promising BST(KCl)3.5 sample from them, followed by Cu doping experiments. The experimental results show that Cu doping significantly improves the crystal quality and density of the alloy, thereby increasing the material's mobility and reducing the resistivity, leading to an improvement in the power factor. However, Cu doping also introduces a large number of dislocations and lattice distortions. Additionally, the highly doped samples contain Cu2Te and BST superlattice structures, which further enhance the scattering of heat transfer phonons, significantly reducing the lattice thermal conductivity. In the experiment, Cu-doped samples exhibited extremely low lattice thermal conductivity, as low as 0.32 W m−1 K−1 at 300 K. These improvements in structure and performance have greatly enhanced the thermoelectric efficiency of Cu-doped samples, leading to a significant increase in their ZT values. Particularly, in samples with a Cu doping level of x = 0.01, the maximum ZT value was 1.47 at 400 K, and the average ZT value reached 1.28 in the temperature range of 300 K to 450 K. These findings underscore the wide-ranging application potential of Cu-doped BiSbTe3 alloys in room temperature refrigeration and power generation. The study provides crucial insights into the characteristics of Cu-doped BiSbTe3 alloys, while also contributing to the optimization of thermoelectric material design and the advancement of sustainable energy conversion technologies. [ABSTRACT FROM AUTHOR]

The simultaneous analysis of perfluoroalkyl substances (PFASs) and lipids in biological tissues is of importance, especially for in situ and microscale analysis, because it provides significant information to understand the relevance of content, composition, and distribution of lipids to the bioaccumulation of PFASs as well as lipid metabolism affected by the biotoxicity of PFASs. In this study, we report the development of a novel ambient mass spectrometry method for the rapid, in situ, and microscale analysis of PFASs and lipids simultaneously in biological tissues for the investigation of their biological correlation. A microscale solid-phase microextraction (SPME) probe with a probe-end diameter of several-μm was employed for in situ and microscale sampling of biological tissues after PFAS exposure. The SPME probe showed a desirable capacity for the enrichment of PFASs and lipid species simultaneously. After sampling and extraction, the loaded SPME probe was directly applied for nanoESI-MS analysis under ambient and open-air conditions. A high-resolution Fourier transform ion cyclotron resonance (FTICR) mass spectrometer operated in the field-induced mode was introduced to record mass spectra using fast polarity switching between positive and negative ion detection. Most of the lipid species were recorded in the positive ion mass spectrum, and PFASs were recorded in the negative ion mass spectrum. By using the developed method, the in situ analysis of PFASs and lipids in the muscle, brain, heart, kidney, liver, and intestine of zebrafish was realized. In addition, simultaneously imaging PFASs and lipids in individual Daphnia magna was successfully achieved for the investigation of their biological correlation. [ABSTRACT FROM AUTHOR]