摘要:AbstractAtomically modified graphitic carbon nitride quantum dots (QDs), characterized by strongly increased reactivity and stability, are developed. These are deposited on arrays of TiO2nanopillars used as a photoanode for the photoelectrochemical water splitting. This photoanode shows excellent stability, with 111 h of continuous work without any performance loss, which outperforms the best‐reported results by a factor of 10. Remarkably, our photoanode produces hydrogen even at zero bias. The excellent performance is attributed to the enhancement of photoabsorption, as well as to the promotion of charge separation between TiO2nanopillars and the QDs.TiO2nanopillars decorated with N‐defects graphitic carbon nitride quantum dotsare developed for water splitting in this work. This photoanode demonstrates excellent photocatalytic stability (more than 110 h of continuous illumination without any performance loss) and produces hydrogen with a rate of 0.8525 µmol·h−1·cm−2even at zero bias.