Tribovoltaic Effect at Liquid–MoS ₂ Interfaces and Spectral Analysis of Interfacial Charge Transfer

Liquid-solid triboelectric nanogenerators (TENGs) offer a viable approach for harvesting water energy to power Internet of Things systems. Semiconductor-based TENGs leveraging the tribovoltaic effect have recently emerged as a focus of research. In this paper, monolayer molybdenum disulfide (ML-MoS₂) is introduced as a contacting material for fabricating direct current (DC) liquid-solid nanogenerators. At the internal liquid-solid interface, electron transfer is strongly evidenced by Raman and photoluminescence spectra. For the external characteristics, macroscopic DC outputs are assessed under various conditions, with a maximum current density of 11.1 mA m^-2. Correlating external output patterns with interfacial charge dynamics, a complete working mechanism of the liquid-solid tribovoltaic effect is better elucidated. This work advances innovative strategies for water energy harvesting, deepening fundamental insights into liquid-solid interactions and the tribovoltaic effect.