Highly sustained seawater electrolysis using the common-ion effect. (a) The schematic diagram depicts the challenge of neutral seawater electrolysis. The electrolysis time comes from (b). (b) The concentration changes of NaCl during the seawater electrolysis with different initial concentrations of NaOH. Calculation conditions: the electrode area is about 0.2 m2; the volume of electrolyte is 3 L; the current density is 500 mA/cm2. (c) The common-ion effect is introduced into seawater electrolysis to improve the electrochemical performance and produce triple product (H2, O2, and NaCl). (d) The solubility of NaCl with different NaOH concentrations.