近日，清华大学唐军旺团队报道了生物激发的铁单原子纳米酶与天然NarGH二聚体协同高效光催化硝酸盐转化。2025年11月10日，《美国化学会志》发表了这一成果。

硝酸盐还原对自然生态修复和化工产业可持续发展至关重要，但受限于硝酸盐向亚硝酸盐转化的限速步骤。

研究组构建了半人工光生物合成平台，将富含氰基的碳氮化物（C₃N₄）负载铁单原子纳米酶（Fe/C₃N₄–CN）与天然NarGH二聚体协同结合：前者模拟NarI亚基的电子传递功能，后者提供生物催化活性，在可见光驱动下实现高效硝酸盐还原。该光生物催化剂在可见光照射下展现出卓越性能：亚硝酸盐选择性接近100%，反应速率常数（k）远超所有已报道的可见光驱动光催化剂，较单独C₃N₄催化剂提升68.9倍；表观催化效率（k_cat/K_M(app)）达1.81×10⁶ M^-1 min^-1，显著优于已知生物酶及仿生纳米材料。

原子与分子层面的机制研究表明，C₃N₄上的铁单原子位点与–C≡N基团分别模拟NarI亚基中的血红素bD与血红素bP，形成独特的生物-非生物界面电子传递链，突破硝酸盐还原的动能瓶颈。该技术为可持续厌氧氨氧化反应提供关键亚硝酸盐原料，同时大幅降低氨生产能耗，具有重要应用前景。

附：英文原文

Title: Bioinspired Fe Single-Atom Nanozyme Synergizes with Natural NarGH Dimer for High-Efficiency Photobiocatalytic Nitrate Conversion

Author: Jiyong Bian, Jing Zhao, Zixuan Zhang, Dongfei Liu, Xianen Lan, Yang Liao, Xiaoqiang An, Diannan Lu, Minmin Liang, Ruiping Liu, Junwang Tang, Huijuan Liu, Jiuhui Qu

Issue&Volume: November 10, 2025

Abstract: Nitrate reduction is of paramount importance for both the restoration of natural ecosystems and the sustainable development of chemical industries but faces challenges in the rate-limiting step of nitrate-to-nitrite conversion. Herein, we demonstrate a semiartificial photobiosynthetic platform that synergistically combines cyano-rich carbon nitride (C3N4)- supported Fe single-atom nanozymes (Fe/C3N4–CN), which mimic the electron transfer function of the NarI subunit, with native NarGH dimers for efficient light-driven nitrate reduction. Under visible light irradiation, the photobiocatalyst exhibits a state-of-the-art capability for nitrate conversion with nearly 100% nitrite selectivity and an unprecedented reaction kinetic constant (k) that far exceeds those of all reported visible-light-driven photocatalysts, corresponding to a 68.9-fold enhancement over the isolated C3N4 photocatalysts. The synergized enzymatic catalytic efficiency (kcat/KM(app)) reaches 1.81 × 106 M–1 min–1, far exceeding those of reported biological enzymes and enzyme-mimicking nanomaterials for nitrate conversion. Mechanistic studies at the atomic and molecular levels reveal that Fe single atoms and C≡N groups on C3N4 mimic the heme bD and heme bP in the NarI subunit, forming a unique electron transfer chain between the biotic–abiotic interface that enables efficient nitrate reduction. This work represents an inspiring approach to overcome the kinetic bottleneck of nitrate-to-nitrite conversion, providing essential nitrite for sustainable anammox reactions and reducing energy consumption for ammonia production.

DOI: 10.1021/jacs.5c07315

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.5c07315