Bifunctional Hydrogen Production and Storage on 0D-1D Heterojunction of Cd0.5Zn0.5S@Halloysites

Development of efficient solar-driven hydrogen (H-2) evolution and H-2 storage materials is challenging. Sulfide nanocatalysts show large potential for H-2 production, but suffer from the drawbacks of inefficient charge separation, serious photocorrosion, and easy agglomeration. Herein, a 0D-1D satellite-core ethylenediaminetetraacetic acid (EDTA)-bridged Cd0.5Zn0.5S@halloysite nanotubes tertiary structure is designed via facile in situ assembly, which settles all the above-mentioned issues and achieves exceptional and stable photocatalytic H-2 evolution and storage. Significantly, EDTA grafted on halloysites as the hole (h(+)) traps steers the photogenerated h(+) and electrons (e(-)) from Cd0.5Zn0.5S separately to halloysites and outer surface Pt sites, achieving efficient directional separation between h(+) and e(-) and inhibiting the h(+)-dominated photocorrosion occurring on Cd0.5Zn0.5S. Benefiting from these advantages, the hierarchy shows an unprecedented photocatalytic H-2 evolution rate of 25.67 mmol g(-1) h(-1) with a recording apparent quantum efficiency of 32.29% at lambda = 420 nm, which is seven-fold that of Cd0.5Zn0.5S. Meanwhile, an H-2 adsorption capacity of 0.042% is achieved with the room temperature of 25 degrees C and pressure of 2.65 MPa. This work provides a new perspective into designing hierarchical structure for H-2 evolution, and proposes an integration concept for H-2 evolution and storage.