  Metal nanoparticles are receiving increased scientific attention owing to
their unique physical and chemical properties that make them suitable for a
wide range of applications in diverse fields, such as electrochemistry,
biochemistry, and nanomedicine. Their high metallic polarizability is a crucial
determinant that defines their electrostatic character in various electrolyte
solutions. Here, we introduce a continuum-based model of a metal nanoparticle
with explicit polarizability in the presence of different kinds of
electrolytes. We employ several, variously sophisticated, theoretical
approaches, corroborated by Monte Carlo simulations in order to elucidate the
basic electrostatics principles of the model. We investigate how different
kinds of asymmetries between the ions result in non-trivial phenomena, such as
charge separation and a build-up of a so-called zero surface-charge double
layer.
