NiCo2S4@Zn0.5Cd0.5S with direct Z-scheme heterojunction constructed by band structure adjustment of ZnxCd1-xS for efficient photocatalytic H2 evolution

Based on hollow spherical NiCo 2 S 4 , Zn x Cd 1-x S with adjustable band structure was used to construct a composite for photocatalytic hydrogen evolution. The hollow spherical structure of NiCo 2 S 4 gives Zn x Cd 1-x S more contact positions to form a stable heterojunction. Through the band structure adjustment for Zn x Cd 1-x S, the induced electron transfer model was transformed into Z-scheme, which effectively enhances the photo-produced carrier separation efficiency of the composite material. At the same time, the fast electron transfer is realized by the great conductivity of the hollow spherical NiCo 2 S 4. This allows the composite material to obtain a shorter average lifetime of PL (0.15 ns) compared to Zn 0.5 Cd 0.5 S (3.9 ns). The composite NiCo 2 S 4 @Zn 0.5 Cd 0.5 S with Z-scheme heterojunction exhibited excellent photocatalytic HER activity and stability due to its unique spatial structure and efficient Z-scheme electron transfer path. The optimized composite NiCo 2 S 4 @Zn 0.5 Cd 0.5 S 1:1 photocatalytic HER rate reached 233.68 μmol . h −1 , which is equivalent to 5.81 times that of Zn 0.5 Cd 0.5 S (40.25 μmol . h −1 ).