Microwave-Assisted Topochemical Conversion of Layered Titanate Nanosheets to {010}-Faceted Anatase Nanocrystals for High Performance Photocatalysts and Dye-Sensitized Solar Cells

The {010}-faceted anatase nanocrystals with controllable crystal size and morphology were synthesized by microwave hydrothermal treatment of layered titanate nanosheet solutions. The nanostructures and formation reaction mechanism of TiO₂ nanocrystals were investigated using X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, and selected-area electron diffraction. Their photocatalytic behavior and dye-sensitized solar cell (DSSC) performance were studied and compared with [111]-faceted anatase nanocrystals and anatase nanocrystals without a specific facet on the surface. There are two kinds of reactions in the formation process of the anatase nanocrystals. One is an in situ topochemical conversion reaction of layered titanate structure to anatase structure, and another is the dissolution–deposition reaction on the particle surface. The microwave hydrothermal process is suitable to control the structural conversion reaction for uniform the crystal size and morphology due to its uniform heating mechanism. The UV–visible spectrum results revealed that the bandgap of the TiO₂ nanocrystals was enhanced in the order of nanocrystal without specific facet < [111]-faceted nanocrystal < {010}-faceted nanocrystal, which corresponded to their photocatalytic activities. The DSSC performance also was enhanced in the same order, suggesting that the {010}-faceted nanocrystals are promising for the high performance DSSCs

Photothermal Ablation of in Situ Renal Tumor by PEG-IR780-C13 Micelles and Near-Infrared Irradiation

PEG-IR780-C13 micelles have been demonstrated to be a novel photothermal agent with tumor-targeting property. This study was designed to explore the feasibility of applying PEG-IR780-C13 micelles and near-infrared (NIR) irradiation for thermal ablation of renal tumor by using an in situ tumor model. In addition, the potential thermal injury to normal renal tissue was evaluated. PEG-IR780-C13 micelles were intended to accumulate in renal tumor after systemic delivery. In vitro results revealed that PEG-IR780-C13 micelles were uptaken by RENCA cells mainly through caveola-mediated endocytosis and mainly distributed in late endosomes and lysosomes. Upon NIR irradiation, PEG-IR780-C13 micelles generated heat effectively both in vitro and in vivo, exhibiting a promising photothermal therapeutic property. The photothermal effect of PEG-IR780-C13 micelles could effectively destroy RENCA cells in vitro and adequately inhibit growth of in situ renal tumor in vivo. Meanwhile, PEG-IR780-C13 micelles mediated photothermal therapy (PTT) resulting in only limited injury to normal renal tissue surrounding tumor sites. Our data indicated that PEG-IR780-C13 micelles mediating PTT could generate tumor-specific heat for destruction of renal tumor in a minimally invasive way, providing a novel strategy for thermal ablation of renal tumor