As an emerging 2D layered material, Bi2O2Se has shown great potential for applications in thermoelectric and electronics, due to its high carrier mobility, near‐ideal subthreshold swing, and high air‐stability. Although Bi2O2Se has a suitable band gap for infrared (IR) applications, its photoresponse properties have not been investigated. Here, high‐quality ultrathin Bi2O2Se sheets are synthesized via a low‐pressure chemical vapor deposition method. The thickness of 90% Bi2O2Se sheets is below 10 nm and lateral sizes mainly distribute in the range of 7–11 µm. In addition, it is found that triangular sheets largely lack “O” content, even only 0.2 for Bi2O0.2Se. The near‐IR photodetection performance of Bi2O2Se nanosheets is systematically studied by variable temperature measurements. The response time, responsivity, and detectivity can approach up to 2.8 ms, 6.5 A W−1, and 8.3 × 1011 Jones, respectively. Additionally, the critical performance parameters, including responsivity, rising time, and decay time, remain at almost the same level when the temperature is changed from 80 to 300 K. These phenomena are likely due to the fact that as‐grown ultrathin Bi2O2Se sheets have no surface trap states and shallow defect energy levels. The findings indicate ultrathin Bi2O2Se sheets have great potentials for future applications in ultrafast, flexible near‐IR optoelectronic devices.

Glucose oxidase (GOx) has been recognized as a “star” enzyme catalyst involved in cancer treatment in the past few years. Herein, GOx is mineralized with manganese-doped calcium phosphate (MnCaP) to form spherical nanoparticles (GOx-MnCaP NPs) by an in situ biomimetic mineralization method, followed by the loading of doxorubicin (DOX) to construct a biodegradable, biocompatible, and tumor acidity-responsive nanotheranostics for magnetic resonance imaging (MRI) and cascade reaction-enhanced cooperative cancer treatment. The GOx-driven oxidation reaction can effectively eliminate intratumoral glucose for starvation therapy, and the elevated H2O2 is then converted into highly toxic hydroxyl radicals via a Mn2+-mediated Fenton-like reaction for chemodynamic therapy (CDT). Moreover, the acidity amplification due to the gluconic acid generation will in turn accelerate the degradation of the nanoplatform and promote the Mn2+–H2O2 reaction for enhanced CDT. Meanwhile, the released Mn2+ ions can be used for MRI to monitor the treatment process. After carrying the anticancer drug, the DOX-loaded GOx-MnCaP can integrate starvation therapy, Mn2+-mediated CDT, and DOX-induced chemotherapy together, which showed greatly improved therapeutic efficacy than each monotherapy. Such an orchestrated cooperative cancer therapy demonstrated high-efficiency tumor suppression on 4T1 tumor-bearing mice with minimal side effects. Our findings suggested that the DOX-loaded GOx-MnCaP nanotheranostics with excellent biodegradability and biocompatibility hold clinical translation potential for cancer management.

The desire for sustainable and clean energy future continues to be the concern of the scientific community. Researchers are incessantly targeting the development of scalable and abundant electro- or photo-catalysts for water splitting. Owing to their suitable band-gap and excellent stability, an enormous amount of transition-metal dichalcogenides (TMDs) with hierarchical nanostructures have been extensively explored. Herein, we present an overview of the recent research progresses in the design, characterization and applications of the TMD-based electro- or photo-catalysts for hydrogen and oxygen evolution. Emphasis is given to the layered and pyrite-phase structured TMDs encompassing semiconducting and metallic nanomaterials. Illustrative results and the future prospects are pointed out. This review will provide the readers with insight into the state-of-the-art research progresses in TMD based nanomaterials for water splitting.

2D materials, represented by transition metal dichalcogenides (TMDs), have attracted tremendous research interests in photoelectronic and electronic devices. However, for their relatively small bandgap (<2 eV), the application of traditional TMDs into solar-blind ultraviolet (UV) photodetection is restricted. Here, for the first time, NiPS 3 nanosheets are grown via chemical vapor deposition method. The nanosheets thinning to 3.2 nm with the lateral size of dozens of micrometers are acquired. Based on the various nanosheets, a linearity is found between the Raman intensity of specific A g modes and the thickness, providing a convenient method to determine their layer numbers. Furthermore, a UV photodetector is fabricated using few-layered 2D NiPS 3 nanosheets. It shows an ultrafast rise time shorter than 5 ms with an ultralow dark current less than 10 fA. Notably, this UV photodetector demonstrates a high detectivity of 1.22 × 10 12 Jones, outperforming some traditional widebandgap UV detectors. The wavelength-dependent photoresponsivity measurement allows the direct observation of an admirable cut-off wavelength at 360 nm, which indicates a superior spectral selectivity. The promising photodetector performance, accompanied with the controllable fabrication and transfer process of nanosheet, lays the foundation of applying 2D semiconductors for ultrafast UV light detection.

The manipulation of magnetism provides a unique opportunity for the development of data storage and spintronic applications. Until now, electrical control, pressure tuning, stacking structure dependence, and nanoscale engineering have been realized. However, as the dimensions are decreased, the decrease of the ferromagnetism phase transition temperature (T c) is a universal trend in ferromagnets. Here, we make a breakthrough to realize the synthesis of 1 and 2 unit cell (UC) Cr2Te3 and discover a room-temperature ferromagnetism in two-dimensional Cr2Te3. The newly observed T c increases strongly from 160 K in the thick flake (40.3 nm) to 280 K in 6 UC Cr2Te3 (7.1 nm). The magnetization and anomalous Hall effect measurements provided unambiguous evidence for the existence of spontaneous magnetization at room temperature. The theoretical model revealed that the reconstruction of Cr2Te3 could result in anomalous thickness-dependent T c. This dimension tuning method opens up a new avenue for manipulation of ferromagnetism.