Simultaneously Broadened Visible Light Absorption and Boosted Intersystem Crossing in Platinum-Doped Graphite Carbon...

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.