Naphthalene is the most abundant polycyclic aromatic hydrocarbon (PAH) found in urban air. It is reactive in the atmosphere under ambient conditions, its chief reaction partner being the hydroxyl radical, OH • . In this work, the reactions of OH • with naphthalene, 1-and 2-naphthol, and 1-and 2-nitronaphthalene were studied in a 9.4 m 3 smog chamber. Relative rates of reaction accorded well with previous studies and allowed estimates to be made of the atmospheric lifetimes of these compounds. Numerous oxidation products were identified, and mechanisms proposed for their formation were based on the further transformation of benzocyclohexadienyl radicals formed by addition of OH • to naphthalene. The naphthols and nitronaphthalenes were deduced not to be on the major reaction pathway to the more oxidized products. Because of the high reactivity of PAH in air, we suggest that priority be given to identifying and quantitating their reaction products, some of which may be relatively persistent air toxics.

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Photonic cancer hyperthermia has been considered to be one of the most representative noninvasive cancer treatments with high therapeutic efficiency and biosafety. However, it still remains a crucial challenge to develop efficient photothermal nanoagents with satisfactory photothermal performance and biocompatibility, among which two-dimensional (2D) ultrathin nanosheets have recently been regarded as the promising multifunctional theranostic agents for photothermal tumor ablation. In this work, we report, for the first time, on the construction of a novel kind of photothermal agents based on the intriguing 2D antimony(III) selenide (Sb 2 Se 3 ) nanosheets for highly efficient photoacoustic imaging-guided photonic cancer hyperthermia by nearinfrared (NIR) laser activation. These Sb 2 Se 3 nanosheets were easily fabricated by a novel but efficiently combined liquid nitrogen pretreatment and freezing−thawing approach, which were featured with high photothermal-conversion capability (extinction coefficient: 33.2 L g −1 cm −1 ; photothermal-conversion efficiency: 30.78%). The further surface engineering of these Sb 2 Se 3 ultrathin nanosheets with poly(vinyl pyrrolidone) (PVP) substantially improved the biocompatibility of the nanosheets and their stability in physiological environments, guaranteeing the feasibility in photonic antitumor applications. Importantly, 2D Sb 2 Se 3 −PVP nanosheets have been certificated to efficiently eradicate the tumors by NIR-triggered photonic tumor hyperthermia. Especially, the biosafety in vitro and in vivo of these Sb 2 Se 3 ultrathin nanosheets has been evaluated and demonstrated. This work meaningfully expands the biomedical applications of 2D bionanoplatforms with a planar topology through probing into new members (Sb 2 Se 3 in this work) of 2D biomaterials with unique intrinsic physiochemical property and biological effect.