Work

Singlet oxygen drives photochemistry in carbon dots–TiO2 composites under visible light

Year: 2026

Type: article

Abstract: Design of heterogeneous photosensitizers capable of selectively generating singlet oxygen (1O2) represents a holy grail in the field of industrial selective organic synthesis. In fact, this highly reactive and specific species is currently generated by using photosensitizers dissolved in homogeneous solutions, while it would be highly desirable to exploit the advantages of heterogeneous catalytic systems for industrial applications. In this work, we demonstrate that composite materials based on carbon dots (CDs) and TiO2, prepared via hydrothermal synthesis, selectively generate singlet oxygen over other reactive oxygen species, in contrast to conventional TiO2-based photocatalysts where activity is mainly driven by hydroxyl and superoxide radicals. The hybrid systems exhibit a markedly enhanced 1O2 photoproduction compared to the single components. This synergistic effect has been correlated with the specific interaction of CDs with TiO2, which in turn is related to the functional groups characterizing the CDs surface. In particular, the prevalent presence of oxygenated moieties at the surface of the CDs stabilizes Ti3+ centers, whose population increases under visible light irradiation. In this case, electron transfer to molecular oxygen is suppressed and singlet oxygen is hypothesized to be efficiently generated through long-range energy transfer mechanisms.

Source: Carbon

DOI: 10.1016/j.carbon.2026.121406

Authors: Alessia Zollo, Alessandro Gottuso, Francesco Parrino, Stefano Livraghi

Institutions: University of Turin, University of Trento

Language: English

Topic: TiO2 Photocatalysis and Solar Cells

Subfield: Renewable Energy, Sustainability and the Environment

Field: Energy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,830

Funder: Dipartimenti di Eccellenza