In studies that mimic natural photosynthesis, a system containing three inde-pendent components, a photosensitizer, electron relay, and catalyst, has been used with a sacrificial electron donor. In this study, we created a novel system for the photocatalytic generation of NADH from aqueous protons using only Pt nanoparticles without any additional photosensitizer, electron relay, and homogeneous organometallic catalyst. We found that irradiation of the Pt nanoparticle solution with visible light converts NAD+ to NADH with a high yield of 86% in the presence of triethanolamine as a sacrificial electron donor. The rate of NADH photogeneration depended on the concentration of PtNPs and TEOA. The rate of NADH generation also increased with NAD+ concentration at low values and reached a plateau.