As a conceptually new class of two-dimensional (2D) materials, the ultrathin nanosheets as inorganic graphene analogues (IGAs) play an increasingly vital role in the new-generation electronics. However, the relatively low electrical conductivity of inorganic ultrathin nanosheets in current stage significantly hampered their conducting electrode applications in constructing nanodevices. We developed the unprecedentedly high electrical conductivity in inorganic ultrathin nanosheets. The hydric titanium disulfide (HTS) ultrathin nanosheets, as a new IGAs, exhibit the exclusively high electrical conductivity of 6.76 × 10(4) S/m at room temperature, which is superior to indium tin oxide (1.9 × 10(4) S/m), recording the best value in the solution assembled 2D thin films of both graphene (5.5 × 10(4) S/m) and inorganic graphene analogues (5.0 × 10(2) S/m). The modified hydrogen on S-Ti-S layers contributes additional electrons to the TiS2 layered frameworks, rendering the controllable electrical conductivity as well as the electron concentrations. Together with synergic advantages of the excellent mechanical flexibility, high stability, and stamp-transferrable properties, the HTS thin films show promising capability for being the next generation conducting electrode material in the nanodevice fields.

A new metallic 2D material with high electrical conductivity (1×10(3) S m(-1)) consists of VSe2 ultrathin nanosheets with 4-8 Se-V-Se atomic layers. This is the first 2D transition-metal dichalcogenide with intrinsic room-temperature ferromagnetism. The nanosheets increase the charge-density-wave transition temperature to 135 K by dimensional reduction.

Perovskite electrocatalysts strongly rely on electronic structure regulation, especially for electron configuration (e g ) and conductivity. However, current regulation strategies inevitably involve ambiguous entanglement of crystals, electrons, and spin degrees of freedom. Here, we developed a spin-state regulation method to optimize oxygen evolution reaction (OER) activity by lattice orientation control of LaCoO 3 epitaxial films. The different lattice-oriented LaCoO 3 films bring different degrees of distortion of the CoO 6 octahedron, successfully inducing a spin-state transition of cobalt from a low spin state (LS t 2g 6 e g 0 ) to an intermediate spin state (IS t 2g 5 e g 1 ). X-ray absorption spectroscopy of Co L-edge and O K-edge provides experimental support of spin-state transition in different lattice-oriented LaCoO 3 films. As expected, LaCoO 3 (100) film possesses optimal e g electron filling, lower adsorption free energy, and higher conductivity, exhibiting better OER performance than the other two films. Our findings demonstrate that electronic state regulation will be a new avenue for the rational design of high-activity perovskite electrocatalysts.