A Synergistic Photocatalysis–Electrocatalysis System for Efficient Hydrogen Generation and Energy‐Saving Benzylamine Oxidative Upgrading

Abstract Photocatalytic hydrogen iodide (HI) splitting represents a promising tactic for H 2 generation, but the light‐shielding effect induced by the generated I 3 − greatly impedes subsequent reactions. A critical challenge in this field lies in achieving the timely reduction of I 3 − while avoiding the use of additional sacrificial agents, such as H 3 PO 2 . Herein, we develop a synergistic photocatalysis–electrocatalysis system to address this challenge and achieve efficient H 2 generation and benzylamine oxidative upgrading. The photocatalytic component features a Re 0.5 Mo 0.5 S 2 cocatalyst‐modified MAPbI 3 with efficient charge separation and ample active sites, achieving a remarkable H 2 generation of 875.4 µmol within 4 h through HI splitting. The subsequent electrocatalytic module can operate at a low potential (only 0.44 V to reach 10 mA cm −2 ) to reduce the generated I 3 − and oxidize benzylamine to value‐added chemicals. After the electrolysis, the regenerated HI solution can be recycled for subsequent photocatalytic H 2 generation. The synergistic system establishes a sustainable catalytic cycle mediated by I − /I 3 − redox couples, enabling continuous photocatalytic H 2 generation from HI splitting and energy‐saving electrocatalytic benzylamine oxidative upgrading.