Work

Nitrate reduction to ammonia catalyzed by GaN/Si photoelectrodes with metal clusters

Year: 2025

Type: article

Abstract: The development of photoelectrochemical cells for reduction of nitrate to ammonia under solar light is of significant interest for the production of clean chemicals and fuels but has remained a daunting challenge. Here, we investigate various metal catalysts supported on GaN nanowires grown on n+-p Si wafer – an emerging functional platform for scalable artificial photosynthesis – and demonstrate highly stable and efficient photoelectrochemical nitrate reduction reaction. We find that Co and Ni catalysts on GaN/Si exhibit the best performance, with an onset potential >0.3 VRHE and a faradaic efficiency of NH3 of 99% at 0.2 VRHE. These results highlight the advantage of photoelectrochemical system in achieving efficient nitrate reduction under more positive potentials. In-situ measurements and theoretical calculations reveal that the binding modes of the $${{{\rm{NO}}}}_{2}^{{-}}$$ intermediate play a key role in the NH3 synthetic process. These results demonstrate that the rational design of catalysts on photoelectrodes can construct synergistic metal-semiconductor interactions for efficient and stable photoelectrochemical NH3 synthesis. This study presents a stable and efficient photoelectrochemical system for nitrate reduction to ammonia using metal catalysts on GaN/Si photoelectrodes, offering valuable insights into catalyst design for sustainable ammonia production driven by solar energy.

Source: Nature Communications

DOI: 10.1038/s41467-025-58372-7