MoS2 nanosheet integrated electrodes with engineered 1T-2H phases and defects for efficient hydrogen production in practical PEM electrolysis

Low electrical conductivity and poor accessibility of MoS2 reaction sites raise great challenges in maximizing the triple-phase-boundary (TPB) sites of MoS2-based electrodes and minimizing ohmic losses for efficient hydrogen evolution reaction (HER) in practical proton exchange membrane (PEM) water electrolysis. Herein, we report a scalable hydrothermal approach to fabricate ionomer-free integrated electrodes with engineered 1 T-2 H het-erophase and defect-rich MoS2 nanosheets (MoS(2)NSs) in-situ grown onto the carbon fiber paper (CFP). With an ultralow loading of 0.14 mg/cm(2), a small voltage of 2.25 V was obtained at 2000 mA/cm(2) in a practical cell with Nafion115 membrane, which outperforms all previously reported high-loading non-precious catalyst-based electrodes. Impressively, it shows 44 times higher mass activity than a high-loading and ionomer-mixed MoS2 assemblies electrode. This work builds a bridge from catalyst optimization to electrode fabrication and provides a promising direction for improving intrinsic catalytic activity, electrode conductivity and stability for practical PEM water electrolysis.

Automated summary

In this study, a scalable hydrothermal approach was developed to fabricate MoS2-based electrodes with engineered 1T-2H heterophase and defect-rich MoS2 nanosheets, which significantly improved the mass activity and stability of the electrode. This work provides a promising direction for improving the catalytic activity, electrode conductivity, and stability in practical proton exchange membrane water electrolysis.