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This paper presents a magnetically levitated-triboelectric nanogenerator to harvest mechanical energy and detect acceleration of the vibatrion in the surroundings. Based on the effective conjunction of triboelectrification and electromagnetic induction, maximum power density of 3.23 W m-3 is obtained at 100 MΩ and 10 m s-2 for the triboelectric part, while the electromagnetic part can provide power density of 2.25 W m-2 at 1 KΩ and 10 m s-2. The hybridized nanogenerator also exhibits a good stability for the output performance and a good charging performance. This hybridized nanogenerator can light up 40 commercial light-emitting diode bulbs and charge a 470 μF capacitor by using a power management circuit. Furthermore, due to the magnetically-levitated structure, the hybridized nanogenerator has been utilized as a vibrometer. It can clearly detect the vibration with the acceleration less than 30 m s-2 and amplitude less than 7.5 mm. This work not only presents a novel approach in the field of mechanical energy harvesting, but also a solid step towards self-powered monitoring technology.

Developing highly dispersed few stacking layer MoS2 nanocatalysts with high exposure of active sites is still a challenge in improving their catalytic activities. Herein, we report a facile strategy for fabricating quasi-single-layer (<3 layers) MoS2/TiO2 nanocatalysts by a novel one-step hydrothermal method using ammonium tetrathiomolybdate (ATM) and P25 (TiO2) as Mo precursor and highly dispersed supporter, respectively. MoS2 nanosheets on MoS2/TiO2 nanocatalysts with the quasi-single layer and slab of less than 10 nm expose maximum active sites of the catalytic anthracene hydrogenation. The results of the catalytic anthracene hydrogenation in slurry-bed reactor show that the quasi-single-layer MoS2/TiO2 nanocatalyst exhibits optimized catalytic hydrogenation performance with the selectivity to deep hydrogenation product (AH8) of 51% and hydrogenation percentage of 41.4%, which were respectively about 5.7 times and twice those of unsupported MoS2 catalyst. The outstanding catalytic activity of anathracene hydrogenation over the resultant quasi-single-layer MoS2/TiO2 can be ascribed to the superior structures of MoS2/TiO2 nanocatalysts. The uniform loading of quasi-single-layer MoS2 nanosheets onto the TiO2 can remarkably enhance the exposure of active sites and effectively avoid the self-aggregation of MoS2 nanosheets.