Fabrication of a single-crystalline SnS-based piezo-assisted efficient single-electrode triboelectric nanogenerator for energy harvesting and sensing applications

Poly(dimethylsiloxane) (PDMS) is extensively used as the negative contact material of triboelectric nanogenerators (TENGs), which can harvest universal mechanical energy. Thus, the main focus of research always lies in the enrichment of the output performance of PDMS-based TENGs with the aid of foreign components. Here, for the first time, we have fabricated a single-crystalline tin sulfide (SnS) and embedded multiwall carbon nanotube (CNT) membrane-based efficient and robust single-electrode triboelectric nanogenerator (S-TENG) for biomechanical energy harvesting applications and investigated the effect of single crystallinity on energy harvesting properties. We synthesized the single crystalline SnS by a facile liquid-phase exfoliation method and the CNT membrane by solvent depletion and vacuum-assisted filtration methods. The creation of the SnS layer on the CNT membrane was done by the vacuum-assisted filtration method and by forming a double-layer structure of CNT-SnS, which serves as the active component for TENG fabrication. As a result, the fabricated S-TENG, i.e. PDMS encapsulated CNT-SnS membrane (CNT-SnS/PDMS), produced an open-circuit voltage of ∼252 V and a short circuit current of ∼16 μA under finger tapping, which are three- and six-fold higher than those of the S-TENG without SnS, respectively. The enhancement of surface charge of the CNT-SnS/PDMS system due to ferroelectric polarization was proved by Kelvin probe force microscopy (KPFM) and COMSOL finite element analysis, which is the main reason for the augmentation in output voltage and current. Furthermore, the fabricated system produces fascinating output through piezoelectric phenomena and several biomechanical motions. Thus, this work provides a facile fabrication technique with a minimal quantity of active material for efficient biomechanical energy harvesting and sensing applications.