Ultrathin 1T-phase MoS₂ nanosheets decorated hollow carbon microspheres as highly efficient catalysts for solar energy harvesting and storage

The composite of MoS₂and hollow carbon sphere (MoS₂@HCS) is prepared via a glucose-assisted one pot synthesis. The composite consists of hierarchical spheres with a diameter of 0.5–4 μm and these hollow spheres are decorated with a number of curled and interlaced MoS₂nanosheets. After the composite is subject to the lithium intercalation, the MoS₂is converted from 2H to 1T phase. In this current work, the activities of 1T-MoS₂@HCS toward photocatalytic hydrogen evolution and the reduction of I₃⁻in dye-sensitized solar cells (DSCs) are systemically investigated. When evaluated as the photocatalyst for hydrogen evolution, the amount of evolved hydrogen over 1T-MoS₂@HCS can reach 143 μmol in 2 h, being 3.6 times higher than as-synthesized 2H-MoS₂@HCS. Additionally, the 1T-MoS₂@HCS can be employed as the counter electrode (CE) material in DSCs. The DSCs based on 1T-MoS₂@HCS CE possesses the power conversion efficiency of 8.94%, being higher than that with 2H-MoS₂@HCS CE (8.16%) and comparable to that with Pt CE (8.87%). Our study demonstrates that 1T-MoS₂@HCS has a great potential as an inexpensive alternative to Pt catalysts.