One-dimensional hierarchical MoO2–MoSx hybrids as highly active and durable catalysts in the hydrogen evolution reaction

Abstract

The hydrogen evolution reaction (HER) is a fundamental process in electrocatalysis and plays an important role in energy conversion through water splitting to produce hydrogen. Finding highly effective and scalable HER catalysts is becoming a very urgent task. In this work, we developed a facile method to synthesize a one-dimensional hierarchical MoO₂–MoS_x hybrid electrocatalyst via the calcination of a one-dimensional (1D) organic–inorganic MoO₃–EDA precursor. The obtained MoO₂–MoS_x hybrids deliver a low onset potential of 155 mV, a low Tafel slope of 51.6 mV dec⁻¹ and excellent cycling stability in acidic electrolytes, suggesting high electrocatalytic activity. Furthermore, MoO₂–MoS₂ exhibited high cycling stability even after 10 h of continuous operation under high overpotential; the current density still remained unchanged. The enhanced HER performances are likely due to high conductivity and more exposed active sites and the effective integration of MoO₂ and MoS_x. In a word, these results fully demonstrated that 1D nanostructured MoO₂–MoS_x hybrid materials may have great potential in future clean energy applications.