Rational design of local microenvironment for electrocatalytic water splitting

Electrocatalytic water splitting reaction kinetics are usually determined by the intrinsic activity of electrocatalysts and the microenvironment at the electrode-electrolyte interface. Compared to electronic structure regulation based on intrinsic activity, manipulating the local microenvironment is more effective at accelerating internal reactions and transfer processes, so herein we concentrate on the latest progress in local microenvironment design for electrocatalytic water splitting. Methods for the development and characterization of the electric double layer structure model closely related to the microenvironment are first introduced. Next, the influence of electrode surface wettability, local pH, interfacial water structure, and electrolyte composition on the composition of interface reactants, key intermediate adsorption, and reaction kinetics are discussed in detail. Local microenvironment design strategies based on bubble engineering, local electric fields, surface modification, interfacial water orientation/hydrogen bonding networks, and electrolyte anion and cation distributions are subsequently proposed. Finally, we outline the existing challenges and provide possible solutions to drive the future development of this emerging field. This summary describes the effects of wettability, local pH, interfacial water structure, and electrolyte composition on the interface reactant compositions, key intermediate adsorption, and reaction kinetics.