Recent Studies on Solid–Liquid Contact Electrification

Solid–liquid interfaces are crucial in basic sciences, such as chemistry, biology, and engineering, particularly in catalysis, electrochemistry, and energy storage technologies. Recent developments in the study of contact electrification at solid–liquid interfaces have led to a paradigm shift from traditional interpretations centered on the electric double layer (EDL) concept. These advancements highlight the critical role of electron transfer at the solid–liquid interface, suggesting that both electrons and ions contribute to form a stern layer. This statement requires a reassessment of our fundamental understanding of interfacial charge dynamics, expanding the range of mechanisms that are at work within this crucial boundary layer. This Spotlight on Applications aims to explore the principles of solid–liquid contact electrification (SLCE) and SLCE-based triboelectric nanogenerator (SLCE-TENG) applications. We also examine the effects of different solids, ranging from semiconductors to insulators, and quantify the effect of liquid triboelectric series on contact electrification. Next, we discuss how to optimize triboelectric outputs through solid and liquid material modifications. We address the applications of these findings in SLCE-TENGs, including energy harvesting, self-powered sensors, and contact electrocatalysis. Finally, we highlight the current challenges and offer perspectives on the electrification of solid–liquid interfaces, providing an outline of future research directions and potential.