In situ growth of MoS2 nanosheets on bimetallic-doped MnNb2O6 nanomaterials for enhanced bifunctional water splitting: DFT insights into adsorption energetics and reaction intermediates

Rapid population growth and energy crises have underscored the demand for sustainable renewable energy sources. In this work, an in situ growth approach was used to anchor MoS 2 (MO-1) onto bimetallic-doped MnNb 2 O 6 (MNO-3) to investigate the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The electrocatalyst exhibited outstanding HER efficacy, delivering a low overpotential of 216 mV , a Tafel slope of 81.7 m V d e c − 1 , and a C dl value of 19.9 m F c m − 2 at 10 m A c m − 2 . It produces an overpotential of 410 mV , a Tafel slope of 238.40 m V d e c − 1 , and C dl value of 1.73 m F c m − 2 at 50 m A c m − 2 for the OER. Furthermore, the TOF of MNO-3@MO-1 was 16-fold higher than that of MNO-1 and 34-fold higher than that of MO-1 for HER. DFT reveals strong electronic coupling, whereas doped Ni and Fe trigger charge redistribution and optimize d-band states to enhance adsorption and kinetics of water splitting.