Highly efficient solar-driven photocatalytic hydrogen evolution by a ternary 3D ZnIn2S4–MoS2 microsphere/1D TiO2 nanobelt heterostructure

Abstract

Combining different semiconductor materials with diverse geometric structures and energy level configurations is an effective strategy for constructing heterostructured photocatalysts with high activity. Using a solvothermal method, 1D TiO₂ nanobelts were uniformly embedded into the gaps of flower-like 3D ZIS/MoS₂ microspheres to allow atomic interactions. Therefore, a 3D ZnIn₂S₄–MoS₂ microsphere/1D TiO₂ nanobelt (ZIS/MoS₂/TiO₂) composite with outstanding hydrogen production performance was synthesized. The unique heterostructure had a favorable energy level distribution and spatial structure, which could improve the interfacial charge transfer. Upon optimizing the weight ratios of the components, the maximum photocatalytic H₂ evolution rate was 8440.28 μmol g⁻¹ h⁻¹ when using the 250%-ZIS/25%-MoS₂/TiO₂ composite under simulated sunlight irradiation, which was ∼44.4 and 2181.0 times higher than when using pure ZIS and TiO₂, respectively. In addition, apparent quantum efficiency (AQE) values of 39.33% at 380 nm and 30% at 420 nm were achieved. Importantly, the hydrogen production rate was 94.1% of the initial rate after four cycles, showing excellent stability. The photocatalytic hydrogen evolution mechanism of the prepared photocatalyst was also discussed in detail.