Electrochemical Sulfion Valorization Using Biphasic Electrolyte and Transition Metal Selenization Simultaneously Enabled by Ionic Liquid

Preventing electrode passivation is a critical challenge in direct electrochemical desulfurization of aqueous solution systems. Here, a hydrophobic imidazole ionic liquid [HMIM]PF 6 was introduced into the electrode and electrolyte for constructing a new sulfide oxidation reaction (SOR) system. [HMIM]PF 6 was utilized as both a phosphating agent and a dopant in the synthesis of catalysts. It promoted the attachment of precursors to nickel foam, which was then fully selenized to form P-, F-, and N-doped Co 0.85 Se/NF. At a potential of only 0.29 V, a current density of 100 mA cm −2 was achieved, with no degradation in catalytic performance observed after 600 h of stability testing. [HMIM]PF 6 incorporated biphasic can prevent sulfur adhesion to the electrodes, because [HMIM]PF 6 accelerates the extraction of SOR products from the electrode phase. The SOR products were identified as S 8 and Na 2 SO 3 , which were successfully extracted using a novel green condensation reflux method, ensuring the recyclability of [HMIM]PF 6 . This work offers a novel approach to improve the electrochemical performance of the SOR. Graphical This article introduces a novel electrochemical sulfide oxidation reaction system utilizing the ionic liquid (IL) ([HMIM]PF 6 ) to effectively reduce sulfur-induced electrode passivation while promoting hydrogen production. The system achieved a current density of 100 mA cm −2 at 0.29 V with stability over 600 h. The biphasic system with [HMIM]PF6 facilitates S 8 and Na 2 SO 3 product extraction and ensures IL recyclability through an ecofriendly reflux method, offering a sustainable route for green H 2 generation and sulfur products recovery.