Synergistically Mo/Fe and N/P Co-Doped Silk Fabric-Derived Carbonaceous Platform for a Flexible, Self-Supported, and Durable HER Electrode Construction

The development of high-performance, binder-free, and mechanically flexible self-supported electrodes is crucial for advancing sustainable hydrogen evolution reaction (HER) technologies. However, HER electrodes with high activity and long-term stability are difficult to construct, primarily because of the binder dependency of conventional powder catalysts and the limited adaptability of rigid metal substrates. Herein, we report an effective strategy for fabricating flexible self-supported electrodes by employing renewable silk fabric as a nitrogen- and carbon-rich precursor, in combination with the synergistic incorporation of multiple non-noble metals (Mo, Fe) and nonmetal heteroatoms (N, P). Through a streamlined impregnation–carbonization process, multiphase active sites were efficiently integrated and strongly coupled within the silk-derived carbon framework. Experimental results demonstrate that the synergistic interactions among these multicomponents considerably optimize HER kinetics. The optimized electrode (Sample 12) delivers a low overpotential of 122.60 ± 2.00 mV at 10 mA·cm–2, together with a high Faradaic efficiency of 96.7%, representing a clear improvement over our previous single-component ammonium-molybdate-loaded system. More remarkably, this electrode exhibits outstanding long-term operational robustness. After continuous operation of the optimized electrode at a large current density of 100 mA·cm–2 for 50 h, its overpotential increases by only 22.08 mV, markedly outperforming commercial Pt/C, which degrades by 148.33 mV, and other silk-derived HER electrodes. Furthermore, comprehensive multiscale characterizations (FESEM, TEM, specific surface area analysis, XPS, XRD, and wettability measurements) were utilized to reveal the mechanism underlying the enhanced HER performance. This work offers a valuable design paradigm for developing low-cost, efficient, and durable industrial-grade flexible electrodes toward large-scale hydrogen production.