Triboelectric nanogenerators as a probe for studying charge transfer at liquid-solid interface

Contact electrification and charge transfer between liquid and solid interfaces are of the most importance for chemistry, energy, catalysis, and even biology. However, the origin of the charges generated and transferred at liquid-solid interfaces remains to be investigated. Recently, triboelectric nanogenerators have emerged as a promising probe for studying charge transfer at liquid-solid interfaces. When a liquid drop moves on a hydrophobic surface, the electric signal generated on electrodes located under the dielectric solid film provides a chance to probe the charge transfer between liquid and solid surfaces. Here, the most recent advances toward a deeper understanding of the charge generated, accumulated, and transferred at liquid-solid interfaces by TENG, as well as the probes design and physical/chemical effects are discussed. The sensing systems and energy conversions enabled by charge transfer at the liquid-solid interface are also included.