Fig. 2: The generation of WE-HE through microbial biofilms.
a Current profile generated by the R. palustris biofilms through evaporation and non-evaporation of water. The shaded area represents one standard deviation. b Relative surface potential maps of the R. palustris biofilm during water evaporation (the inset is the atomic force microscopy (AFM) topography image). c Schematic diagram of the electricity generation induced by evaporation in the biofilm and the scanning electron microscopy (SEM) image of the R. palustris biofilm. d Spontaneous evaporation of water in the negatively charged nanochannels in the biofilm. e The diffusion current (Idiffuse) and the opposing streaming current (Isc) arised from ionic gradient and coulomb forces, respectively. f Electroactive microorganisms uptake extracellular hydrovoltaic electrons. Data represent mean ± SD from n = 3 technical replicates. Scale bars: 1 μm in (c).
