Electron Beam-Induced Microstructural Evolution of SnS2 Quantum Dots Assembled on N-Doped Graphene Nanosheets with Enhanced Photocatalytic Activity

Development of photocatalysts for degradation of organic pollutants with low-cost and robust stability remains as one of the most serious challenges. Herein, SnS2 quantum dots (QDs)/N-doped graphene nanocomposites (SNGNSs) are successfully prepared by combining a hydrothermal process with an electron-beam irradiation (EBI) technique. Due to the enhanced light absorption and efficient separation of photogenerated electrons and holes, the resultant SNGNSs display excellent photodegradation ability for methyl orange (MO). Additionally, it is found that an EBI treatment could further improve the photocatalytic activity of SNGNSs. Particularly, the as-prepared SNGNSs irradiated under 70 kGy exhibit a photodegraded rate of 95.6% for the degradation of MO within 60 min, which is greatly superior to that of the unirradiated one (59.5%). The enhanced photocatalytic performance can be ascribed to the doping of nitrogen element into graphene nanosheets, the enhanced crystallinity of SnS2 QDs as well as the creating lattice defects in SnS2 QDs. This work suggests that EBI treatment is an effective strategy to modify the surface of graphene-based nanocomposites, which displays widely potential applications for constructing carbon-based photocatalysts with excellent catalytic ability and developing high-performance photoelectronic devices.