Two-dimensional (2D) materials show great promise for building next-generation memristors. However, their application in self-rectifying memristors (SRMs)—crucial for suppressing sneak-path currents in high-density arrays—is still underexplored. In this work, we address this gap by developing ultrathin non-layered Co₃O₄ nanosheets through a vapor-phase growth strategy and precisely engineering their oxygen vacancies (O_V) for high-performance SRMs. Our synergistic approach, combining salt-assisted vapor–liquid–solid, hydrate-assisted, and spatial confinement methods, enables the controlled synthesis of high-quality Co₃O₄ nanosheets as thin as 0.46 nm with a single-atomic-layer thickness. We demonstrate that magnetically driven rapid thermal annealing (MD-RTA) effectively increases the O_V concentration from 15.15% to 33.15%, as quantitatively confirmed by X-ray photoelectron spectroscopy (XPS), Raman, and Kelvin probe force microscopy (KPFM). The resulting memristor exhibits excellent self-rectifying resistive switching behavior, with a high rectification ratio exceeding 10⁴ and a large ON/OFF ratio over 10⁴. The device also achieves high switching uniformity (coefficient of variation, C_v = 0.0979), stable cycling endurance over 100 direction current (DC) cycles, and room-temperature operation. This study provides a reliable synthesis route for 2D non-layered materials and highlights defect engineering as an effective strategy for developing advanced in-memory computing devices with inherent crosstalk immunity.

Strain engineering offers an effective strategy to break the intrinsic symmetry of two-dimensional (2D) materials, thereby enabling tunable anisotropic responses and broadening their functional versatility. However, achieving novel anisotropic behaviors through strain engineering remains challenging and lacks systematic study. Here, mixed-dimensional 2D/one-dimensional (1D) heterostructures were constructed using monolayer WSe₂ and SiO₂ nanorods, where the diameter of SiO₂ nanorods effectively regulated the strain in monolayer WSe₂ to investigate its anisotropic responses. The WSe₂ at strained interfaces exhibits tunable photoluminescence enhancement, modulated bandgap, and the emergence of polarized photoluminescence by adjusting the diameter of the nanorods. Interestingly, an unexpected in-plane ferroelectricity was observed in monolayer WSe₂ at the heterointerface. Additionally, the heterostructure photodetectors demonstrate outstanding overall performance with a broadband detection range from 375 to 808 nm, a competitive photoswitching ratio of ~ 3200, a high detectivity of 2.4 × 10⁹ Jones, and a fast response speed of ~ 11.3 ms. Another interesting finding is that the photodetectors demonstrate polarization-dependent detection with a tunable dichroic ratio ranging from 1 to 1.51. The heterostructure detectors can reliably capture sequential images of the capital letter “H”. This study provides an effective strategy for tailoring the anisotropic responses of TMDCs and further endowing their diverse functionalities and applications.