Inhibition of H ₂ and O ₂ Recombination: The Key to a Most Efficient Single‐Atom Co‐Catalyst for Photocatalytic H ₂ Evolution from Plain Water

In the present work, it is shown that anodic TiO2 nanotubes (NTs) can be decorated with Pt, Pd, Rh, and Au single atoms (SAs) by a simple “dark deposition” approach. Such NTs surface trapped noble metal SAs provide high activity for photocatalytic H2 generation from pure water, i.e., in absence of sacrificial agent. However, metals also act as active centers undesired hydrogen back-oxidation (H2 + O2 → H2O), leading to decrease overall production efficiency. Here reported use co-catalysts, form atoms, inhibit this recombination. From different noble-metal investigated, Pd yield highest rate 0.381 µmol h−1 cm−1 at density 0.41 × 105 µm−2. Overall, results path highly efficient performance water splitting suppression H2/O2 recombination, which effectively achieved using co-catalysts.