Jun Zhu,Songrui Wei,Jie Tang,Yi Hu,Xiaoyu Dai,You Zi,Mengke Wang,Yuanjiang Xiang,Weichun Huang
Recently, novel two-dimensional materials, e.g., Xenes (graphdiyne, phosphorene, bismuthene, antimonene, etc.) and MXenes, have drawn great attention in nanophotonics due to their excellent flexibility, high photothermal conversion efficiency, and large thermal conductivity. Although the Xenes and MXenes have achieved rapid progress in many fields over the past decade, their relatively poor photodetection and nonlinear photonics have still limited their practical applications. In this work, a mixed-dimensional 2D MXene V2CTx nanosheet (NS)/0D bismuth quantum dot (Bi QD)-based heterostructure fabricated by a combination of selective etching and the hydrothermal method was simply deposited onto a clean poly(ethylene terephthalate) substrate with an embedded regular Ag lattice to prepare a flexible photoelectrochemical (PEC) electrode. The PEC result shows that the as-fabricated flexible electrode not only exhibits significantly improved photocurrent density (32.7 μA cm–2) and photoresponsivity (906 μA W–1) compared to individual MXene V2CTx NSs and Bi QDs but also displays high stability with a stable photocurrent density even after 200 bending cycles at 60°. Taking advantage of the Kerr effect of both MXene V2CTx NSs and Bi QDs, an all-optical switcher based on this mix-dimensional heterostructure for the spatial cross-phase modulation has also been realized with a preferred modulation depth. Density functional theory calculations provide direct evidence for the strong internal built-in electric field (7.3 × 107 eV m–1) created by the heterostructure for the enhancement of both photodetection and nonlinear photonics. The integration of Xenes or MXene-based mixed-dimensional heterostructures provides a concept and fundamental guidance to construct next-generation optoelectronic and photonic devices.
Dianchun Qiu,Kai Zheng,Tuxiang Guan,Zemei Li,Juan Peng,Qing Tao,Kelan Yan,Ningzhong Bao
Flexible supercapacitor is highly important to future wearable textile electronics and metaverse technologies, yet they are still limited by their unfulfilled specific capacitance and energy density . Here, a MXene (V 2 CT X ) based fiber fabric (MFF) was developed via a synergistic flow driven assembly strategy for high-performance supercapacitors . Adapted through reliable approaches of indirect etching, organic cation intercalation, and wet spinning, the MFF presents rich active sites, ordered paths, a moderate specific surface area (41.1 m 2 g −1 ), good flexibility and reproducibility. Admirably, the resulting fibrillar meshwork structure was found to be highly conducive to increasing energy density and reducing the electrochemical polarization. In this regard, a relatively good capacitance of 731 F g −1 is achieved at a current density of 0.5 A g −1 in H 2 SO 4 electrolyte. Furthermore, the assembled asymmetric solid-state supercapacitor (FSC) exhibits high specific capacitance of 401.2 F g −1 at 0.5 A g −1 , long cycle stability (5000 cycles) and high mechanical flexibility (5000 bending cycles). Benefiting from this outstanding electrochemical performance , the FSCs using EMIBF 4 /PVDF-HFP as electrolyte can be implied as reliable power source to flexible displaying and health monitoring. This work provides a novel MXene (V 2 CT X ) based fiber fabric for constructing flexible electrode, promising to open an avenue toward wearable devices.
危险品化学品经营许可证（带存储）