Interface Engineering of Energy and Mass Transport Enhancing Solar‐Driven Photocatalytic CO₂ Reduction into Fuels

Abstract The reaction interface plays a vital role in solar‐driven photocatalytic CO 2 reduction into fuels, orchestrating fundamental processes ranging from photon capture and energy conversion to reactant transport and surface reactions. Persistent challenges, including substantial thermal dissipation and insufficient CO 2 supply at the interface, severely compromise catalytic performance. Herein, a holistic interface design strategy is proposed for boosting CO 2 reduction by synergistically optimizing catalyst distribution and regulating the reaction microenvironment. The developed interface integrates a porous catalyst matrix promoting light penetration and fluid flow, a heat insulation structure maximizing photothermal utilization, and gas‐permeable microchannels ensuring continuous CO 2 supplementation to active sites while facilitating product desorption. When implemented with a ZnIn 2 S 4 model catalyst, this versatile interface demonstrates a CO yield of 0.567 µmol h −1 in the CO 2 reduction experiment, achieving a notable 4.5‐fold performance enhancement compared to the traditional liquid phase reaction. Comprehensive investigations into the energy and mass transfer mechanism reveal that the increase in catalytic activity stems from synergistic effects, including optimized photon flux transmission, elevated local temperature through thermal confinement, and maintained high CO 2 concentration around the catalyst. These findings collectively validate the effectiveness and universality of the proposed interfacial modulation method, offering novel insights for promoting solar fuel synthesis.