Electronic reconstruction at the interface of MoS2/1T-WS2 heterojunction induced by Cr doping: synthesis and computation of efficient water decomposition catalysts

Two-dimensional transition-metal dichalcogenides (TMDs) are commonly used in catalytic reactions due to their inexpensive and easy-to-prepare nature, but the monolithic structure limits their applicability to overall water splitting. In this work, for the first time, we introduce single-atom Cr doping at the interface of a MoS 2 /1T-WS 2 heterojunction, achieving a synergistic reconstruction of the interfacial electronic structure and the built-in electric field, thereby simultaneously activating the key steps of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). In 1 M KOH, Cr@MoS 2 /WS 2 requires only 145 mV (HER) and 181 mV (OER) at 10 mA cm −2 , and it remains stable during continuous operation for 72 h at 100 mA cm −2 . Spectroscopy and density functional theory (DFT) jointly reveal enhanced Cr–S coordination and d/p-orbital hybridization, along with regulation of the band gap and band-center, establishing a generalizable paradigm from interfacial doping to electronic reconstruction and ultimately to performance improvement. This interfacial doping strategy can be generalized for multifunctional catalytic modification of other transition metal disulfides. • An efficient Cr@MoS 2 /WS 2 catalyst for water splitting is developed via a two-step method. • Cr introduction creates Cr–S bonds, altering atomic arrangement and electron distribution. • Characterization and DFT calculation verified the surface features of the catalysts. • Cr doping changes atomic arrangement and charge distribution, enhancing nucleophilicity. • Cr@MoS 2 /WS 2 shows excellent OER and HER performance with superior stability.