No abstract

The double network (DN) hydrogel has attracted great attention due to its wide applications in daily life. However, synthesis DN hydrogel with excellent mechanical properties is still a big challenge. Here, polyacrylamide/copper‐alginate double network (PAM/Cu‐alg DN) hydrogel electrolyte is successfully synthesized by radiation‐induced polymerization and cross‐linking process of acrylamide with N, N’‐methylene‐bis‐acrylamide and subsequent cupric ion (Cu2+) crosslinking of alginate. The content of sodium alginate, absorbed dose, and the concentration of Cu2+ are investigated in detail for improving the overall properties of PAM/Cu‐alg DN hydrogel electrolyte. The PAM/Cu‐alg DN hydrogel electrolyte synthesizes by radiation technique and Cu2+ crosslinking shows superior mechanical properties with a tensile strength of 2.25 ± 0.02 MPa, excellent energy dissipation mechanism, and the high ionic conductivity of 4.08 ± 0.17 mS cm−1. PAM/Cu‐alg DN hydrogel is characterized with attenuated total reflection Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and X‐ray photoelectron spectroscopy analyses and the reason for the improvement of mechanical properties is illustrated. Furthermore, PAM/Cu‐alg DN hydrogel electrolyte exhibits excellent strain‐sensitivity, cyclic stability, and durability. This work paves for the new way for the preparation of DN hydrogel electrolytes with excellent properties.

Development of noble-metal-free electrocatalysts with low cost, facile synthesis, and high efficiency for the hydrogen evolution reaction (HER) is attracting increasing attention. Two-dimensional (2D) MXenes have recently emerged as one of the most promising conductive supports for HER electrocatalysis. Herein, we report a facile gamma radiation strategy for the one-step modification of Ti3C2 MXene and its coupling with amorphous molybdenum sulfide (MoS x ) to form modified Ti3C2-supported MoS x (MD-Ti3C2/MoS x ) hybrids with a 2D/2D structure. The modification of the Ti3C2 MXene, the content of amorphous MoS x , and the active sulfur ratio of the hybrids can be easily controlled by adjusting the absorbed dose. MD-Ti3C2/MoS x with an optimal absorbed dose of 100 kGy shows efficient electrocatalytic performance for the HER with a Tafel slope of 41 mV dec–1, a low overpotential of 196 mV at a current density of 50 mA cm–2, and durable stability. The great enhancement in HER performance could be attributed to the strong 2D/2D interfacial coupling, the highly enhanced electron-transfer process, and more exposed electrocatalytic active sites. With the facile and easy scale-up gamma radiation strategy, this study offers an effective method for the synthesis of the Ti3C2 MXene-based hybrid with efficient HER performance, which could be potentially extended to the synthesis of other MXene-based hybrids.