Effects of interfacial acid-base on the performance of contact-separation mode triboelectric nanogenerator

Triboelectric nanogenerator (TENG) has demonstrated huge potential in biomedical monitoring, robotic sensors, industrial environmental monitoring, and so on. The harsh environment with different pH may have direct impacts on the performances of TENG. In this work, we systematically investigated the effects of interfacial acid-base on the performance of contact-separation mode TENG. The Fourier transform infrared spectroscopy (FTIR) exhibited the accelerating effect of acidebase on hydrolysis of polydimethylsiloxane (PDMS). Contact electrification on PDMS surfaces in macro and nanoscale both showed the increased charge densities with the increase of the H+ and OH- concentration, respectively. X-ray photoelectron spectroscopy (XPS) and FTIR of the PDMS with different contact cycles indicated the heterolytic cleavage of the main chain upon contact, which can produce mechano radicals and induce electron transfer from SiO2 to this lowest free molecular orbital (LUMO) of the PDMS naturally. More produced mechano radicals by cleavage induce more electron transfer, contributing to the increasing trend of contact electrification with ion concentration. These results have revealed the effect mechanism of acidebase on the polymer-based TENG's performance, which can provide guidance for the development of polymer-based TENGs and self-powered smart sensors in harsh environment. (C) 2021 Elsevier Ltd. All rights reserved.