Lu Zhang,Zhongjun Li,Jiang Liu,Zhengchun Peng,Jia Zhou,Han Zhang,Yingchun Li
Two-dimensional (2D) transition-metal/metal chalcogenides including MoS2, MoSe2, WS2, SnS2, etc. have shown considerable potential for the fabrication of gas sensors for NO2 detection. However, these sensors usually suffer from sluggish and incomplete recovery at room temperature, and their sensitivities are limited by presorbed O2. In this work, a novel optoelectronic gas sensor based on direct-bandgap InSe nanosheets was demonstrated. Because of the excellent photoelectric and sensing properties in few-layer InSe, detection of NO2 at room temperature was realized. Ultrahigh and reversible responses were obtained under ultraviolet (UV) light illumination, and the limit of detection (0.98 ppb) was ∼40 times lower than that observed without UV light. Furthermore, the effects of O2 and H2O molecules on sensor performance were fully studied through experiments and density functional theory. Some new mechanisms of NO2 detection in high relative humidity conditions under UV illumination were proposed, including regulation of proton transfer and induction of H2O2 reduction. In all, this work not only broadens the application field of 2D InSe, but also demonstrates the potential prospect of detecting ppb-level NO2 in complex circumstances such as human breath by using 2D material-based sensors with light activation.
Chi Huang,Zhengbo Sun,Haodong Cui,Ting Pan,Shengyong Geng,Wenhua Zhou,Paul K. Chu,Xue-Feng Yu
Near-infrared-II (NIR-II) biowindow is appealing from the perspectives of larger maximum permissible exposure in comparison with the near-infrared-I biowindow, so the NIR-II-responsive drug-delivery nanoplatform is highly desirable. In this work, two-dimensional InSe nanosheets (InSe NSs) are modified with poly(ethylene glycol) and evaluated as an effective NIR-II-responsive cancer treatment nanoplatform. The InSe NSs synthesized by liquid exfoliation exhibit prominent NIR-II-responsive photothermal conversion efficiency (39.5%) and photothermal stability. Moreover, the InSe NSs have a doxorubicin (DOX) loading capacity as high as 93.6%, along with excellent NIR-II-responsive DOX release characteristic. The superior synergistic chemo/photothermal effects have also been demonstrated by the in vitro experiments in killing cancer cells. In combination with good biocompatibility, the InSe NSs have great potential in therapeutic applications.
Indium selenide (InSe) has become a research hotspot because of its favorable carrier mobility and thickness-tunable band gap, showing great application potential in high-performance optoelectronic devices. The trend of miniaturization in optoelectronics has forced the feature sizes of the electronic components to shrink accordingly. Therefore, atomically thin InSe crystals may play an important role in future optoelectronics. Given the instability and ultralow photoluminescent (PL) emission of mechanically exfoliated ultrathin InSe, synthesis of highly stable mono- and few-layer InSe nanosheets with high PL efficiency has become crucial. Herein, ultrathin InSe nanosheets were prepared via thermal annealing of electrochemically intercalated products from bulk InSe. The size and yield of the as-prepared nanosheets were up to ∼160 μm and ∼70%, respectively, and ∼80% of the nanosheets were less than five layer. Impressively, the as-prepared nanosheets showed greatly enhanced stability and PL emission because of surface modification by carbon species. Efficient photoresponsivity of 2 A/W was achieved in the as-prepared nanosheet-based devices. These nanosheets were further assembled into large-area thin films with photoresponsivity of 16 A/W and an average Hall mobility of about 5 cm2 V–1 s–1. Finally, one-dimensional (1D) InSe nanoscrolls with a length up to 90 μm were constructed by solvent-assisted self-assembly of the exfoliated nanosheets.
危险品化学品经营许可证（带存储）