Activation of patternable ceramics for hydrogen evolution reaction using molybdenum-based fillers†

Abstract

Hydrogen is considered a promising alternative to conventional fossil fuels, as it can be easily produced from renewable energy sources. While electrocatalytic water splitting can achieve near-unity faradaic efficiency in producing hydrogen from water, the widespread implementation of large-scale water electrolysis is hindered by reliance on costly platinum group metal-based electrocatalysts. Here, we report on the rational design of Molybdenum-containing SiCN composites (Mo–SiCN) through an active-filler controlled pyrolysis (AFCOP) strategy. Our investigation into the composite's microstructural evolution revealed the formation of a Mo_4.8Si₃C_0.6 Nowotny phase at a relatively low temperature of 1000 °C. After optimization, the resulting catalyst demonstrated a Tafel slope below 95 mV dec⁻¹ and an overpotential near 575 mV at a normalized current density of 1 mA μF⁻¹. As a proof of concept, the AFCOP strategy was employed to engineer a crack-free Mo–SiCN micropattern, enabling the miniaturization of a Pt-free electrochemical water splitting (EWS) reactor. Produced via soft lithography, the Mo–SiCN pattern exhibits feature sizes ranging from 10 to 200 μm, with near-net-shape replication and a Young's modulus of ≈60 GPa.