Preparation of Heavily Doped P-Type PbSe with High Thermoelectric Performance by the NaCl Salt-Assisted Approach

Abstract

Thermoelectric (TE) technology, which can convert scrap heat into electricity, has attracted considerable attention. However, broader applications of TE are hindered by lacking high-performance thermoelectric materials, which can be effectively progressed by regulating the carrier concentration. In this work, a series of PbSe(NaCl)x (x = 3, 3.5, 4, 4.5) samples were synthesized through the NaCl salt-assisted approach with Na+ and Cl− doped into their lattice. Both theoretical and experimental results demonstrate that manipulating the carrier concentration by adjusting the content of NaCl is conducive to upgrading the electrical transport properties of the materials. The carrier concentration elevated from 2.71 × 1019 cm−3 to 4.16 × 1019 cm−3, and the materials demonstrated a maximum power factor of 2.9 × 10−3 W m−1 K−2. Combined with an ultralow lattice thermal conductivity of 0.7 W m−1 K−1, a high thermoelectric figure of merit (ZT) with 1.26 at 690 K was attained in PbSe(NaCl)4.5. This study provides a guideline for chemical doping to improve the thermoelectric properties of PbSe further and promote its applications.

Recent advances of piezo‐catalysis and photocatalysis for efficient environmental remediation

“…Industries such as food processing, paper production, textile, printing, and tanneries primarily bear the responsibility for generating wastewater contaminated with dyes [9][10][11]. On a global scale, approximately 800,000 metric tons of dyes are produced annually, with textile dyes accounting for roughly 200,000 metric tons of this total [12][13][14]. Dye wastewater encompasses a diverse array of contaminants, among which one can find substances such as adhesives, salts, acids, and auxiliaries.…”

“…Photocatalysis comprises a sequence of key phases (Figure 3): (1) light absorption by a photocatalyst guiding to the creation of electrons and holes (e À and h þ ), (2) the movement of carriers from the interior of the photocatalyst to its surface, and (3) redox reactions occurring on the surface of the photocatalyst [60][61][62]. The generation of free charges and the degradation effect bears a greater resemblance to piezo-catalysis, and the way they participate in redox reactions was elucidated in reactions (13) to (19) as previously published [63].…”