The rapidly growing market of portable and wearable smart electronics has created strong interest in flexible electrode materials with high specific capacitance and fast charging/discharging properties. However, high mass-specific capacitance active materials are often limited by the low areal mass-loading required. High areal capacity electrodes can make more efficient use of the limited internal space of these miniature devices by minimizing the volume and weight taken by current collectors and separators. Herein, a method is proposed to prepare a nickel–cobalt layered double hydroxide binder-free cathode on flexible carbon cloth with a mass loading of 20 mg cm −2 . This core–shell hybrid structure prepared using a MOF self-sacrificing template, achieves a high energy density using thick electrodes while improving their slow kinetics by enhancing both the ion diffusion process and charge transfer dynamics. The areal capacitance reaches a staggering 4.42 mAh cm −2 (31.79 F cm −2 ) at a current density of 8 mA cm −2 . Furthermore, a one-step hydrothermal method to prepare the FeNi-S anode (1.67 mAh cm −2 , 2 mA cm −2 ) is proposed. Upon assembling with the gel electrolyte, this flexible device possesses an impressive energy density of 3.29 mW h cm −2 (3 mW cm −2 ). It can readily supply energy to watches, wireless e-paper, LEDs, and can be anticipated to be widely used in next-generation high-performance portable and wearable devices.
Photo-assisted electrocatalysis has arisen as a promising approach for hydrogen generation by incorporating photocatalysts into electrocatalysts. 2D SnS 2 is a photocatalyst that absorbs visible light. However, the rapid recombination of photo-generated electron-hole pairs significantly reduces the overall photocatalytic efficiency of SnS 2 , limiting its practical application. Thus, this study prepares an in situ heterojunction SnS 2 @SnO 2 using a one-step hydrothermal method. The degradation efficiency of methyl orange (MO) using SnS 2 @SnO 2 is measured, achieving a degradation rate of 92.75% within 1 h, which is 1.9 times higher than that of pure SnS 2 . Additionally, FeNiS/SnS 2 @SnO 2 is synthesized and exhibited significant improvements in the photo-assisted oxygen evolution reaction (OER). It achieves an overpotential of 260 mV and a Tafel slope of 65.1 mV dec −1 at 10 mA cm −2 , showing reductions of 11.8% and 31.8%, respectively, compared to FeNiS alone. These enhancements highlight the strong photo-response capability of SnS 2 @SnO 2 . Under the internal electric field of SnS 2 @SnO 2 , the photogenerated electrons in the conduction band of SnS 2 quickly move toward SnO 2 , facilitating efficient photocatalytic reactions. FeNiS, with a lower Fermi energy level (E F ), facilitates electron transfer from SnS 2 @SnO 2 and enhances OER performance by efficiently participating in the reaction. This study paves a new path for 2D photocatalyst materials.