Spindle-shaped medium-entropy metal telluride nanostructures as high-performance dual-catalytic electrocatalysts for overall water splitting

The development of low-cost and high-activity electrocatalysts is crucial for clean energy production and sustainable development. In particular, non-noble-metal-based medium-entropy materials (MEMs) have recently attracted considerable attention because of their excellent electrocatalytic performance and have become a new research hotspot in the field of electrocatalysis. Additionally, the fewer main elements allow MEMs to be easily recycled and synthesized, with potential industrial applications. Inspired by these advantages, spindle-shaped (Fe 2 CoNi)Te 2 medium-entropy metal telluride (METe) nanostructures were prepared via in situ Te doping during thermal treatment of metal–organic frameworks (MOFs). The resulting spindle-shaped (Fe 2 CoNi)Te 2 METe prepared with an optimal ratio of Fe 2 CoNi-MOF and the tellurium powder exhibits excellent electrocatalytic activity and stability for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), achieving low overpotentials of 155 and 263 mV at 10 mA cm −2 for the HER and OER, respectively, and outstanding stability in 60 h tests. Density functional theory calculations demonstrate that the enhanced performance of the medium-entropy (Fe 2 CoNi)Te 2 METe nanostructures is attributed to a significant increase in the surface charge density, a substantial increase in the *H adsorption/desorption ability and a remarkable reduction in the Gibbs free energy of the rate-determining step due to the d-band center being closer to the Fermi level. This study provides a feasible strategy for achieving efficient and low-cost electrocatalysts.