ZnIn 2 S 4 Heterojunctions Constructed with In-MOF Precursor for Photocatalytic Hydrogen Evolution without Cocatalysts.

Znln2 S4 has great prospects for photocatalytic water splitting to hydrogen by visible light. Herein, a novel Znln2 S4 -In-MOF (ZnInM S4 ) photocatalyst is elaborately synthesized by in situ method with In-MOF as the template and In3+ as the source. ZnInM S4 overcomes the fast interface charge recombination and a sluggish charge lifetime via the formed heterojunctions. Photoelectrochemical measurements reveal that the charge-transfer kinetics is enhanced since In-MOF is introduced to act as a reliable charge-transport channel. ZnInM S4 exhibits outstanding cocatalyst-free H2 evolution rate of 70 μmol h-1 under irradiation (λ > 420 nm), which is 3.2-fold higher than that of Znln2 S4 . In addition, the ZnInM S4 photocatalyst shows good stability in the 16 h continuous reaction. This work illustrates the feasibility of the MOF precursor instead of inorganic salts to directly synthesize photocatalysts with high performance.