Enhanced thermoelectric properties of Cu1.8S via introducing Bi2S3 and Bi2S3@Bi core-shell nanorods

• Published in: Journal of alloys and compounds 2017-12, Vol.727, p.1076-1082
• Main Authors: Zhang, Yi-Xin, Ge, Zhen-Hua, Feng, Jing
• Format: Article
• Language: English
• Subjects: Alloys; Bi2S3 nanorods; Bismuth sulfides; Core-shell structure; Cu1.8S; Electric properties; Figure of merit; Mechanical alloying; Nanorods; Plasma sintering; Power factor; Spark plasma sintering; Temperature; Thermoelectric materials; Thermoelectric properties; Thermoelectricity; Toxicity; Transport properties
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2017.08.224

Digenite (Cu1.8S) as a low-cost, low-toxicity thermoelectric material attracts more and more attention due to its excellent electrical transport. In this paper, the Bi2S3 and Bi2S3@Bi core-shell were introduced to Cu1.8S bulk prepared by mechanical alloying (MA) and spark plasma sintering (SPS) technique. The core-shell structural nanorods were synthesized by a hydrothermal method using Bi2S3 nanorods as the template. The effects of adding Bi2S3 on the thermoelectric properties of Cu1.8S were investigated in detail at the temperature between 323 K and 723 K. The power factor of Cu1.8S was enhanced by introducing Bi2S3@Bi core-shell nanorods due to improved Seebeck coefficient. A maximum thermoelectric figure of merit (ZT) value of 0.77 was attained at 723 K due to optimized thermal transport properties and to the maintained electrical transport properties, which is 2.4 times higher than that of the pristine Cu1.8S (0.32 at 723 K). •Cu1.8S dispersed with x wt% Bi2S3 (x = 1, 3, 5) and 3 wt% Bi2S3@Bi core-shell nanorods were fabricated by MA combined with SPS.•The properties of p-type Cu1.8S were enhanced by introducing n-type Bi2S3 nanorods.•Bi2S3@Bi core-shell nanorods benefit to optimize Seebeck coefficient and reduce thermal conductivity.•The highest ZT value reaches abouna t 0.77 at 723 K for Cu1.8S bulk sample with 3 wt% Bi2S3@Bi core-shell nanorods.