Self-sensitized photochlorination of benzo[a]pyrene in saline water under simulated solar light irradiation

Cation Radical Induced Photochlorination of Naphthalene in Saline Water under UV Light Irradiation

“…For instance, pyrene (Pyr), a PAH with a prolonged lifetime of its singlet state (650 ns) in cyclohexane and has a Δ G ET S1 of −1.4 eV as shown in Table S2, photochlorination reaction occurred via the Pyr + · pathway . On the other hand, B­[a]P underwent a photochlorination reaction via the [ 3 B­[a]­P*- 1 O 2 ] pathway, due to the shorter lifetime (49 ns) of 1 B­[a]­P* . The photoreaction of B­[a]P was triggered by 3 B­[a]­P*, and the photochlorination process proceeded via the [ 3 B­[a]­P*- 1 O 2 ] pathway.…”

“…These intermediates subsequently react with Cl – to finalize the chlorination process. In our previous research, we found that the excited benzo­[a]­pyrene (B­[a]­P) and oxygen complexes ([ 3 B­[a]­P*- 1 O 2 ]) were capable of reacting with Cl – to form 6-chlorobenzo­[a]­pyrene (6-ClB­[a]­P) in saline water under sunlight irradiation. Recent studies have demonstrated that pyrene cation radicals (Pyr + ·), which are formed through electron transfer between singlet state pyrene ( 1 Pyr*) and O 2 , can undergo nucleophilic reactions with Cl – to generate 1-chloropyrene (1-ClPyr) .…”

“…Recent studies have demonstrated that pyrene cation radicals (Pyr + ·), which are formed through electron transfer between singlet state pyrene ( 1 Pyr*) and O 2 , can undergo nucleophilic reactions with Cl – to generate 1-chloropyrene (1-ClPyr) . Numerous past studies on the photochlorination of PAHs have introduced acetonitrile or dimethyl sulfoxide into the reactive aqueous solution to improve the solubility of PAHs . Significantly, the incorporation of these organic solvents could modify the reaction mechanism, as organic solvents often impact the electron transfer efficiency between the excited state of PAHs and O 2 , unlike in natural water environments .…”

Artificial photosynthesis bringing new vigor into plastic wastes

“…After that, the resulting PS radicals underwent the β‐scission process, thus leading to the cleavage of stable C–C linkages and the product formation. Organic photocatalysts could realize the conversion of PS into valuable chemicals, but some drawbacks from the organic molecule, including self‐sensitization and limited light absorption, would incur the decreased catalytic activity 130,131 . In light of this, inorganic photocatalysts have been deemed as reliable catalysts owing to their outstanding advantages like controllable structure and strong stability, which render them more suitable for long‐term plastic conversion.…”

“…Organic photocatalysts could realize the conversion of PS into valuable chemicals, but some drawbacks from the organic molecule, including self-sensitization and limited light absorption, would incur the decreased catalytic activity. 130,131 In light of this, inorganic photocatalysts have been deemed as reliable catalysts owing to their outstanding advantages like controllable structure and strong stability, which render them more suitable for long-term plastic conversion. For instance, the PS deconstruction into value-added chemicals over inorganic photocatalyst was explored by Ma et al 59 Intriguingly, the temperature parameter might be one of the factors that influence the PS valorization performance, since tiny products were detected under thermal conditions and the thermally-driven PS conversion (4%) was achieved.…”