  Electrosorption is a promising technique for brackish water deionization and
waste water remediation. Faradaic materials with redox activity have recently
been shown to enhance both the adsorption capacity and the selectivity of
electrosorption processes. Development of the theory of electrosorption with
redox active materials can provide a fundamental understanding of the
electrosorption mechanism and a means to extract material properties from
small-scale experiments for process optimization and scale-up. Here, we present
an intuitive, physics-based equivalent circuit model to describe the
electrosorption performance of redox active materials, which is able to
accurately fit experimental cyclic voltammetry measurements. The model can
serve as an efficient and easy-to-implement tool to evaluate properties of
redox active materials and help to distinguish between the transport-limited
and reaction-limited regimes in electrosorption processes. And the extracted
intrinsic material properties can be further incorporated into process models
under lower supporting electrolyte concentrations for realistic electrosorption
applications.
