Study of the impact of gas flow and thermal motion of gas molecules on charge transfer at the gas-solid interface

Triboelectrification (TE) has attracted considerable attention since the invention of triboelectric nanogenerators (TENGs), revealing significant potential for harvesting high-entropy energy, which is challenging to convert into electricity using conventional methods. Several studies have explored the mechanisms of TE at the interface between solids and liquids. However, a model for the gas-solid interface remains to be developed. In this study, a gas-solid friction nanogenerator (GS-TENG) was developed to quantify charge transfer at the gas-solid interface. The effects of gas flow and the thermal motion of gas molecules on charge transfer at the gas-solid interface were investigated. The results indicated that charge transfer at the gas-solid interface primarily relied on the thermal motion of the gas molecules to supply the necessary energy. The main effect of the gas flow was to alter the frequency of gas-molecule collisions with the solid surface, suggesting that it is not a prerequisite for charge transfer at the gas-solid interface. Additionally, the principle of similarity between TE and charge dissipation at the gas-solid interface was explored. This study demonstrates the potential of the GS-TENG to harvest the kinetic energy of gas molecules and may provide better insight into TE.