Electrochemical Crystallization in Aqueous Electrolytes: Unlocking the Complex Chemistry of a Seemingly Simple Molecule

Compared to other synthetic routes, electrochemical synthesis offers unique control of the reaction rate, or current density J . Recently, interest in electrochemical crystallization from aqueous electrolytes has resurged, driven in part by water’s inherent reactivity. Spontaneous proton production (H 2 O ↔ H + + OH – ) presents both challenges and unique opportunities. In this Review, we first explore the key physicochemical processes involved in aqueous electrocrystallization of metals, a simpler group of materials with well-defined lattice structures. We then turn our attention to critical considerations for growing more complex compounds, characterized by intricate lattice symmetries and stoichiometries. We argue that achieving precision control in aqueous electrochemical crystallization requires a holistic understanding of proton activity and the ability to regulate interfacial chemical kinetics and transport phenomena across multiple length scales. With such control, electrochemical crystallization in aqueous systems offers a sustainable platform for the precision synthesis of materials essential to energy technologies and sustainability.