Confined dual‐interface <scp>HRGO</scp> / <scp> Cu ₂ O </scp> @ <scp>CuMOF</scp> heterojunction for enhanced photothermal methanol/water reforming to hydrogen

Abstract Photothermal‐driven methanol/water reforming offers as a sustainable route for low‐temperature, on‐site hydrogen (H 2 ) production by coupling solar energy with liquid fuel compatibility. Herein, a HRGO/Cu 2 O@CuMOF core‐shell heterojunction catalyst was in situ constructed via a homologous coordination etching strategy. This design introduces dual‐interface synergy and confined spatial architecture: HRGO‐Cu + interface enhances water adsorption and activation, accelerating OH· radical generation for C–H bond cleavage in methanol; Cu 2 O‐CuMOF junction facilitates charge separation and stepwise dehydrogenation through spatially confined intermediate transformation. Benefiting from this cooperative architecture, the catalyst achieves a high H 2 production rate of 77.2 mmol g cat −1 h −1 at 210°C, nearly 8 times of thermal reforming, with activation energy significantly reduced by 29.6%. Notably, the catalyst can initiate H 2 generation as low as 100°C, and maintains excellent activity and integrity over 72 h. This work offers a scalable strategy for constructing MOF‐based heterojunctions with confined interface synergy, advancing sustainable photothermal H 2 production.