Porphyrinic Metal‐Organic Framework‐Based Heterojunction Composites for Enhanced Photocatalytic Hydrogen Evolution

Abstract A dual‐solvent strategy is developed to enable uniform deposition of transition metal sulfide (Ni 3 S 4 or CoS 2 ) nanoparticles onto the surface of the porphyrinic metal‐organic framework (MOF) PCN‐222(Zn). This approach allows the construction of heterojunction composites with a well‐defined interface and efficient charge separation, and the resulting PCN‐222(Zn)‐Ni 3 S 4 composites demonstrate enhanced photocatalytic hydrogen evolution activity under UV–vis light with a 47‐fold enhancement over pristine PCN‐222(Zn) or a 16‐fold enhancement over nickel sulfide alone. The heterojunction design further stabilizes the photocatalyst during prolonged irradiation and enables consistent recyclability without significant activity loss. This work highlights the potential of heterojunction engineering with MOF and transition metal sulfide for the development of efficient, stable, and earth‐abundant photocatalysts for sustainable hydrogen production.