Fig. 4: The spin-selected electron transfer model for liquid–solid CE.
From: Spin-selected electron transfer in liquid–solid contact electrification

The spin-selected electron transfer at the O2-containing liquid and ferrimagnet interface (a) without a magnetic field and (b) with a magnetic field. c The magnetic field-induced T-S spin conversion of the [HO2• •e−] radical pair. d The vector representation of the T0-S conversion of the [HO2• •e−] radical pair. B denotes the magnetic field strength.