Nanoscaling and Heterojunction for Photocatalytic Hydrogen Evolution by Bimetallic Metal‐Organic Frameworks

Abstract Using sunlight to manufacture hydrogen offers promising access to renewable clean energy. For this, low‐cost photocatalyst with effective light absorption and charge transfer are crucial, as current top‐performing systems often involve precious metals like Pd and Pt. An integrated organic–inorganic photocatalyst based on the cheap metals of iron and nickel are reported, wherein the metal ions form strong metal‐sulfur bonds with the organic linker molecules (2,5‐dimercapto‐1,4‐benzenedicarboxylic acid, H₄DMBD) to generate 2D coordination sheets for promoting light absorption and charge transport. The 2D sheets are further modified through ionic metal‐carboxylate moieties to allow for functional flexibility. Thus, high‐surface‐area thin nanosheets of this 2D material, with an optimized Fe/Ni ratio (0.25:1.75), and in heterojunction with CdS nanosheet, achieve a stable photocatalytic hydrogen evolution rate of 12.15 µmol mg⁻¹ h⁻¹. This work synergizes coordination network design and nano‐assembly as a versatile platform for catalyzing hydrogen production and other sustainable processes.