Herein, taking
graphite carbon nitride ( g-C3N4) as the example, we demonstrated that the two limiting factors that determine the
photosensitization performance, namely, light absorption and intersystem crossing (ISC), could be simultaneously enhanced through Pt2+ doping. Specifically, as a π-conjugated two-dimensional
semiconductor,
g-C3N4 is capable of absorbing light shorter than 460 nm (2.7 eV). Upon Pt2+ doping that allows
metal-to-
ligand charge transfer (MLCT) from Pt2+ to the substrate
g-C3N4, the light absorption of
g-C3N4 was greatly expanded up to 1000 nm. Meanwhile, the large atomic number of Pt2+ ensures promotion of ISC to activate the triplet state of
g-C3N4 via heavy atom effect (HAE), which was confirmed via both
photosensitization performance and photophysical characterizations. Further, the enhanced light absorption and
photosensitization of Pt2+-doped
g-C3N4 were harvested for
antibiotics removal, a type of environment contaminants that gained global attention because of their worldwide abuse. Compared with its undoped counterpart, Pt2+-doped
g-C3N4 featured significantly improved
antibiotics removal in the presence of low-power white LED irradiation, which is promising for photosensitized environmental remediation.