The synergetic combination of defect engineering and graphene coupling enables to develop an effective way of exploring efficient bifunctional electrocatalyst/electrode materials. Defect-engineered amorphous MoO2-reduced graphene oxide (rGO) nanohybrid was synthesized by soft-chemical reduction of K2MoO4 in graphene oxide colloids. Mo K-edge X-ray absorption spectroscopy clearly demonstrates the rutile-type local atomic structure of amorphous MoO2 with significant oxygen vacancies and intimate electronic coupling with rGO. The defect-introduced MoO2-rGO nanohybrid shows excellent bifunctionality as electrocatalyst for hydrogen evolution reaction and electrode for sodium-ion batteries, which are superior to those of crystalline MoO2-rGO homologue. The beneficial effect of simultaneous defect control and rGO coupling can be ascribed to the provision of oxygen vacancies acting as active sites, the increase of electrical conductivity, and the improvement of reaction kinetics.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. NRF‐2020R1A2C3008671, No. NRF‐2017R1A5A1015365). This work was also supported by National R&D Program through the National Research Foundation of Korea (NRF) funded by Ministry of Science and ICT (No. 2021M3H4A1A03049662). The experiments at PAL were supported in part by MOST and POSTECH.
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- amorphous nanocrystal
- defect engineering
- hydrogen evolution electrocatalyst
- sodium ion batteries