N–Co–S Single‐Atom Electronic Bridge Enables a Z‐Scheme Heterojunction for Room‐Temperature Photocatalytic Hydrogen Production From Ammonia Decomposition

Ammonia (NH 3 ) decomposition to hydrogen (H 2 ) offers a sustainable route for clean energy generation, benefiting from abundant feedstocks, ease of storage and zero‐carbon cycle. Conventional NH 3 decomposition, however, relies on Ru‐based noble metal catalysts and requires temperatures above 400°C, resulting in high cost and limited scalability. The development of efficient, low‐cost catalysts that operate under mild conditions is therefore imperative. Here, we report a novel Z‐scheme photocatalyst composed of Co‐doped CdS quantum dots anchored on NH 2 ‐MIL‐53(Al) (Co‐CdS QDs/MIL) via an interfacial N–Co–S single atom electron bridge (Co‐SAEB). By precisely steering the separation and migration of photogenerated charges, this architecture drives efficient photocatalytic NH 3 decomposition at ambient temperature. The catalyst achieves an exceptional H 2 evolution rate of 18 µmol·g −1 ·s −1 , surpassing existing photocatalytic systems and approaching the performance of photothermal NH 3 decomposition processes. Combined characterization and theoretical analyses reveal that the Co‐SAEB is pivotal in establishing a direct Z‐scheme charge‐transfer pathway, which suppresses carrier recombination and enhances both redox capability and photocatalytic durability. This work advances the fundamental understanding of Z‐scheme electron transfer and provides a design strategy for highly active, stable and adaptable photocatalytic materials.