Co-crystal of Ti4Ni2 and Ti8Ni4 clusters with enhanced photochemical properties

Abstract

Many titanium-oxo clusters (TOCs) with various structure types have been reported, but research on co-crystallized TOCs still remains very rare. Herein, we successfully isolated heterometallic {Ti₈Ni₄+ Ti₄Ni₂} with co-crystal arrangement. Because of the Ni-to-TiO and Ti₄Ni₂-to-Ti₈Ni₄ charge transfer, cluster {Ti₈Ni₄+ Ti₄Ni₂} shows wide light absorption and narrow band gap based on the ultraviolet-visible spectra and density functional theory calculations. Moreover, the cluster co-crystallization and more metal centers in cluster {Ti₈Ni₄+ Ti₄Ni₂} endow it with better photocurrent response and photocatalytic hydrogen evolution activity than {Ti₄Ni₂} alone. This work not only provides a new model for co-crystallized TOCs but also stimulates research interest in their photochemical performances.