Boosting photoelectron transport in Zn0.5Cd0.5S/Sn3O4 heterostructure through close interface contact for enhancing photocatalytic H2 generation and degradation of tetracycline hydrochloride

Reasonable design and construction of heterogeneous photocatalysts with close interface contact are considered as the effective strategy to realize the application of highly efficient solar for hydrogen evolution and pollutant degradation. Here, a novel Zn0.5Cd0.5S nanospheres/Sn3O4 nanosheets (ZCS/SO) heterostructure photocatalyst was firstly synthesized using a simple hydrothermal method, where Zn0.5Cd0.5S nanospheres in-situ grew on the surfaces of Sn3O4 nanosheets derived by ultrasonicating Sn3O4 nanoflowers. The synthesized ZCS/SO heterostructure exhibited much higher photocatalytic activity for H2 production and tetracycline hydrochloride (TCH) degradation than pristine Sn3O4 and Zn0.5Cd0.5S. The optimal ZCS/SO-10 performed the highest rate of hydrogen production of 7.19 mmol·g−1·h−1, which was 112.3 and 3.6 times those of Sn3O4 and Zn0.5Cd0.5S, respectively. And the AQY of ZCS/SO-10 for H2 evolution was up to 16.6 % at λ = 420 nm. Moreover, ZCS/SO-10 displayed the highest TCH degradation rate (0.0484 min−1), which were 228.3 and 1.9 times those of Sn3O4 (0.000212 min−1) and Zn0.5Cd0.5S (0.0249 min−1). Such excellent dual-functional photocatalytic performance of ZCS/SO heterostructure could be attributed to the synergistic effect between Sn3O4 and Zn0.5Cd0.5S as well as the formation of heterogenous interfaces with close contacts, which greatly increased specific surface area, enlarged spectral response range, enhanced hydrophilicity and accelerated photogenerated charge transfer, resulting in the improvement of photogenerated charge yield and photoreaction efficiency. Detailed electron transport mechanisms and possible degradation paths of TCH were also proposed. This work provides a feasible strategy for the preparation of transition metal sulfide photocatalysts efficiently utilizing solar energy to realize the production of clean energy and water environmental remediation.