Ultrasonic exfoliated ReS₂ nanosheets: fabrication and use as co-catalyst for enhancing photocatalytic efficiency of TiO₂ nanoparticles under sunlight

Rhenium disulfide (ReS₂) is an interesting kind of transition metal dichalcogenide (TMD) because of its thickness-independent and suitable direct-bandgap structure, which could enable highly efficient solar-energy conversion efficiency. Here, we demonstrate an ultrasonic liquid exfoliation technique in combination with grinding to produce high quality ReS₂ nanosheets (NSs) on a large scale. After combination with TiO₂ nanoparticles, the co-catalytic performance of TiO₂@ReS₂ nanocomposites is investigated, which presents dramatically enhanced degradation activity of organic pigments under sunlight illumination in comparison with pure TiO₂ nanoparticles. The underlying mechanism of enhanced photocatalytic activity can be attributed to improved separation efficiency of photogenerated electron–hole pairs in TiO₂@ReS₂ nanocomposites, which is confirmed by photoluminescence analysis and photoelectrochemical measurements. Our results demonstrate that the layered ReS₂ NS is a promising two-dimensional supporting platform for photocatalysis and moreover it could also provide a new perspective on TMDs co-catalyst. (paper)