In this work, porous Co₃O₄ materials were prepared via a solid-state conversion process of a freshly prepared cobalt-based metal–organic framework (Co-MOF) crystal. Herein, the unique Co-MOF crystal was formed via the specific chemical coordination between the carboxylic ligand azobenzene-3,5,4′-tricarboxylic acid (H₃ABTC) and the auxiliary ligand 4,4′-bipyridine (bpy) to construct 2-dimensional (2D) bilayer structural intermediates, which subsequently formed a 3D polycatenation supramolecular array architecture with the assistance of π–π stacking and hydrogen bonding interactions. Subsequently, porous Co₃O₄ particles were obtained by simple thermolysis of the Co-MOF crystals via a two-step calcination treatment. The results demonstrated that the as-made Co₃O₄ displays crystalline and well-defined porous features and can be applied as a supercapacitor electrode, and its energy storage performances were investigated in 2 M KOH electrolyte. The electrochemical results showed that the porous Co₃O₄ particles exhibit a high specific capacitance of 150 F g⁻¹ at a current density of 1 A g⁻¹ and retain slightly enhanced capacitance after 3400 cycles, which could be ascribed to its higher specific surface area and accessible channel structural features. The present approach is facile, controllable, and reproducible. Importantly, this specific solid-state thermal conversion strategy could be easily extended to prepare other porous metal and/or metal oxide nanomaterials with specific surface textures and morphologies.

TiO₂ is an ideal photocatalyst candidate except for its large bandgap and fast charge recombination. A novel laminated junction composed of defect‐controlled and sulfur‐doped TiO₂ with carbon substrate (LDC‐S‐TiO₂/C) is synthesized using the 2D transition metal carbides (MXenes) as a template to enhance light absorption and improve charge separation. The prepared LDC‐S‐TiO₂/C catalyst delivers a high photocatalytic H₂ evolution rate of 333 µmol g⁻¹ h⁻¹ with a high apparent quantum yield of 7.36% at 400 nm and it is also active even at 600 nm, resulting into a 48 time activity compared with L‐TiO₂/C under visible light irradiation. Further theoretical modeling calculation indicates that such novel approach also reduces activation energy of hydrogen production apart from broadening the absorption wavelength, facilitating charge separation, and creating a large surface area substrate. This synergic effect can also be applied to other photocatalysts' modification. The study provides a novel approach for synthesis defective metal oxides based hybrids and broaden the applications of MXene family.

To achieve the wearable comfort of electronic skin (e-skin), a capacitive sensor printed on a flexible textile substrate with a carbon black (CB)/silicone rubber (SR) composite dielectric was demonstrated in this paper. Organo-silicone conductive silver adhesive serves as a flexible electrodes/shielding layer. The structure design, sensing mechanism and the influence of the conductive filler content and temperature variations on the sensor performance were investigated. The proposed device can effectively enhance the flexibility and comfort of wearing the device asthe sensing element has achieved a sensitivity of 0.02536%/KPa, a hysteresis error of 5.6%, and a dynamic response time of ~89 ms at the range of 0–700 KPa. The drift induced by temperature variations has been calibrated by presenting the temperature compensation model. The research on the time–space distribution of plantar pressure information and the experiment of the manipulator soft-grasping were implemented with the introduced device, and the experimental results indicate that the capacitive flexible textile tactile sensor has good stability and tactile perception capacity. This study provides a good candidate for wearable artificial skin.