Ce-doped derived dual-phase 1T/2H-MoS2: a promising catalyst for highly efficient electrocatalytic oxygen evolution reaction

Abstract

Designing and developing highly active and stable oxygen evolution reaction (OER) electrocatalysts remains a major challenge in water splitting. Molybdenum disulfide (MoS₂) is a promising low-cost electrocatalyst, but its application is limited by intrinsically low oxygen evolution reaction (OER) activity. In this work, Ce-doped dual-phase 1T-2H MoS₂ electrocatalysts with 7%, 10%, and 13% Ce (denoted as Ce–MoS₂-1, Ce–MoS₂-2, and Ce–MoS₂-3) were synthesized via a hydrothermal method, respectively. Ce doping induces the formation of flower-like nanosheet architecture and the coexistence of the 1T-2H dual-phase, which is beneficial to expose abundant active sites and facilitate charge transfer for efficient electrocatalytic performance. The optimum phase-induced Ce–MoS₂-2 demonstrates superior OER activity with a low overpotential (η₁₀ = 215 mV) and overall water splitting voltage (1.562 V@10 mA cm⁻²), retaining stability for 40 h. In situ Fourier transform infrared (FT-IR) spectroscopy and Raman spectroscopy reveal that Ce–MoS₂-2 undergoes transformation to MoOOH at a reconstruction potential of 1.6 V. Density functional theory calculations revealed that the enhanced conductivity and strengthened Mo–O interactions in Ce–MoS₂-2 could facilitate oxygen radical adsorption and reaction kinetics. This study provides valuable insights for designing transition metal dichalcogenide (TMD) catalysts toward high-efficiency overall water splitting.