Hydrogen has been considered as one of the most promising renewable energy for production and storage. Here, we report an efficient method to synthesize MoS2-MoO2 composite by hot-injection method using MoO3 and S powder as precursors with oleic acid (OA) and oleylamine (OLA) as solvent, respectively. The X-ray diffraction shows the presence of the peaks from both MoS2 as well as MoO2. With increasing reaction temperature and time, oleic acid reorganizes the octahedral units of MoO3 and gradually turn into low valence of Mo. After injecting S-precursor, OLA first reduces Mo-precursor to MoO2 as core, and then S atoms replace O atoms to form MoS2 as shell, eventually forming MoS2-MoO2 core-shell structure. MoO2 with few-layer MoS2 can be observed by transmission electron microscope. A Tafel slope of 129 mV/dec is obtained for MoS2-MoO2 composite, which is much better than MoS2 and MoO2. The enhanced HER performance is attributed to the abundance active sites from MoS2 and the improved charge transfer direction by MoO2.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Process Chemistry and Technology
- Surfaces, Coatings and Films
- Materials Chemistry