Controlled fabrication of Ru–O–Se composites for enhanced acidic oxygen evolution

Developing relatively cost-effective and high-performance Ru-based composites as electrocatalysts for acidic oxygen evolution has become the critical step toward emerging renewable energy conversion, in which exploring controllable synthetic strategies and investigating the intrinsic nature by non-metallic interfacial modulation is highly desirable. In this work, a facile tandem process is proposed by ball-milling and thermal annealing for the scalable synthesis of Ru–O–Se nanocomposites with in-situ formed crystalline RuSe2 and metallic Ru heterostructures on a RuO2 substrate. The optimized RuOxSey-800 sample has been proved to have an excellent OER activity and long-term stability in an acidic electrolyte due to its suitable microscopic morphology and phase composition, along with a relatively smaller Tafel slope of 45.4 mV dec−1 compared with commercial RuO2 and most similar catalysts reported in the literature. The outstanding acidic OER performance can be ascribed to the enhanced electron transfer and more active site exposure by controllable selenization. This work paves a novel way for the design and large-scale production of various non-metallic modified composite catalysts for extensive applications of energy conversion and storage.