Design of few-layered 1T-MoS2 by supramolecular-assisted assembly with N-doped carbon quantum dots for supercapacitor

Abstract

1T phase molybdenum disulfide decorated by N-doped carbon quantum dots (MoS2/NCQDs) is successfully synthesized by supramolecular-assisted method. N-doped carbon quantum dots (NCQDs) derived from citric acid and thiourea can form a supramolecular structure through hydrogen bonding, which spurs the formation process of MoS2 at a molecular level. The results demonstrate that NCQDs in supramolecular system and NH3 coming from thiourea effectively prevent the agglomeration of MoS2, resulting in the formation of 1T-MoS2 with a wide interlayer spacing about 0.95 nm. The as-prepared MoS2/NCQDs-6 possesses an excellent supercapacitive performance (379.5F g−1 at 0.5 A g−1) and outstanding rate capability (269.7F g−1 at 10 A g−1) under the synergy of NCQDs and 1T phase MoS2. The fabricated flexible asymmetric supercapacitor delivers an optimal energy density of 33.5 Wh kg−1 at 722.0 W kg−1. The excellent supercapacitive response should be contributed to the wide interlayer spacing of 1T-MoS2 which can improve the faster ion diffusion and the introduction of NCQDs which can offer a good electrical conductivity and enhance the hydrophilic property of the material. This work illumines a simple effective way to fabricate practical used 1T MoS2 hybrid electrode materials for supercapacitor.