Defect-Engineered ReS₂ Nanoparticles on NiS₂ Nanosheet Heterostructures as Bifunctional Electrocatalysts for Overall Water Splitting

Design and preparation of freestanding bifunctional ordered structural catalysts with superior activity, low cost, and good reversibility, are crucial for commercial water-splitting applications. In this study, a durable and effective NiS₂/ReS₂ (NRS) electrocatalyst is successfully fabricated using various quantities of Re source on carbon cloth (CC) by a facile solvothermal method. Upon changing the quantities of the Re source, the catalyst dimensions and shape undergo substantial changes, enabling the control of the catalytic activity of NRS. In particular, the optimal NRS-50@CC displays remarkable catalytic performance for oxygen and hydrogen evolution reactions, revealing small overpotentials of 244 mV at 20 mA cm⁻² and 108 mV at 10 mA cm⁻², respectively, as well as notable stability. Moreover, the NRS-50@CC (+, −) cell device requires a voltage of ≈1.56 V at 10 mA cm⁻². This paper proposes a novel approach for the construction of durable bifunctional electrocatalysts using exceptionally active layered metal chalcogenide materials.