A Tribo‐Chemoelectric Coupled Nanogenerator for Dual‐Modal Sensing of Salt Solutions

ABSTRACT The accurate detection of salt concentration and ionic composition is vital for chemical manufacturing and environmental monitoring. However, existing portable detectors are typically reliant on an external power supply and are unable to simultaneously measure a wide range of concentrations and provide reliable discrimination of key cations, including K + , Na + , Ca 2+ , and Mg 2+ . To address these challenges, we report a tribo‐chemoelectric coupled nanogenerator (TCNG) for self‐powered dual‐modal sensing of salt solutions. Through a simple structural modification of a conventional droplet‐based triboelectric nanogenerator (TENG), which involves exposing a 10 mm segment of the lower electrode at the bottom edge of the device, effective coupling between triboelectric and chemoelectric signals is realized within a single‐structure, single‐loop configuration. The resulting device enables highly sensitive and broad‐range concentration detection (0–3500 mmol·L − 1 ) with a sensitivity of −500.76 µA·(mol·L − 1 ) − 1 below 0.5 mol·L − 1 , while achieving 92.5% accuracy in multi‐ion recognition. This work provides a feasible strategy for self‐powered electrochemical sensing and offers a promising route for high‐performance, on‐site salt analysis within industrial and environmental settings.