Fig. 2: Catalyst-dependent photoelectrochemical nitrate reduction.
From: Nitrate reduction to ammonia catalyzed by GaN/Si photoelectrodes with metal clusters
a Energy band diagram of metal/GaN/Si photoelectrode under light illumination. b Faradaic efficiency of NH3 for metal catalysts loaded on GaN/Si. The measurement was conducted in 0.1 M K2SO4 with 0.5 M KNO3 at various cathodic potentials (0.3 to −0.8 VRHE) under 1 sun light illumination. Faradaic efficiency of H2, NH3, \({{{\rm{NO}}}}_{2}^{{-}}\), and N2H4 for c GaN/Si, d Cu/GaN/Si, e Co/GaN/Si, and f Ni/GaN/Si. Co and Ni catalysts showed the highest FENH3 (>98%) among the tested samples.
