Construction ZnIn2S4/Ti3C2 of 2D/2D heterostructures with enhanced visible light photocatalytic activity: A combined experimental and first-principles DFT study

Multidimensional nano-heterostructures with unique dimensionality-dependent integrative and synergic effects have been valued but are still underdeveloped. In this study, bulk Ti3AlC2 was stripped into monolayer Ti3C2 (TC) and fabricated into aggregated ZnIn2S4 (ZIS) nanosheets to construct a 2D/2D ZnIn2S4/Ti3C2 nanosheet heterojunction. The ZIS/TC-30 composites exhibited excellent photocatalytic activity; the malachite green (30 mg/L) degradation rate constant reached approximately 0.0382 min−1, and the hydrogen evolution rate was up to 9172 μmol·h−1·g−1. Experiments and theoretical studies (DFT) revealed the synergistic effects between ZIS and TC. On the one hand, TC effectively prevented the aggregation of ZIS nanosheets, which was beneficial for ZIS to expose more active sites and expand the interface contact area. On the other hand, TC with outstanding metallic conductivity provided a fast channel to accelerate photogenerated electron-hole separation and transfer in the ZIS/TC composites. This work will provide definitive guidance for designing a multidimensional heterostructure photocatalyst for strengthened visible-light photocatalytic ability.