Synergistic band engineering and interface regulation in carbon- and iron- doped BNNS/SWCNT composite films for enhanced thermoelectric performance
作者：Aoxuan Zhang, Xiaoliang Ma, Si Chen, Yunfei Zhang*, Can Jiang, Weiyi Wang*, Feipeng Du*
关键字：Single-walled carbon nanotubes, Boron nitridenanosheets, Thermoelectric materials
论文来源：期刊
具体来源：Chemical Engineering Science
发表时间：2026年
Single-walled carbon nanotubes (SWCNTs) are considered highly promising flexible thermoelectric materials because of their excellent electrical transport properties, mechanical flexibility, and solution processability. However, their thermoelectric performance is still limited by the difficulty of simultaneously optimizing electrical conductivity and the Seebeck coefficient. In this work, semiconducting nonmetallic carbon- and metallic iron-doped exfoliated hexagonal boron nitride nano-sheets (BNNSs) have been firstly synthesized by high temperature pyrolysis and microwave-assisted synthesis method, respectively. Then, the as-prepared C(Fe)-doped BNNSs are incorporated into SWCNT networks to construct composite films with designed hetero-interfaces for improved thermoelectric performance. The introduction of Fe-BNNSs and C-BNNSs creats abundant heterointerfaces, inducing an energy-filtering effect and increasing the Seebeck coefficient. Notably, C-BNNS forms a conformal coating on SWCNTs, and C-BNNS enhances π-π interactions with SWCNTs, improving their dispersion and facilitating carrier transport. Meanwhile, the stable coated heterojunction synergistically boosts electrical conductivity and the Seebeck coefficient, further enhancing thermoelectric properties. In this system, carbon doping plays a dual role by simultaneously realizing band engineering of BNNSs and interfacial regulation within the SWCNT network, whereas iron doping mainly contributes through band structure modulation. As a result, the optimized C-BNNS/SWCNT composite film achieves a maximum power factor of 389.7 μW m-1 K-2. In addition, the assembled thermoelectric device delivers a normalized power density of 1.9 × 10 W m-1 K-2. Therefore, this work demonstrates that element-doped BNNSs serve as efficient nano-fillers to modulate charge transport behavior and interfacial properties in SWCNT films, which offers a feasible route toward high-performance carbon nanotube-based thermoelectric composites.