Divalent Heterometal Doped Titanium-Oxide Cluster Polymers: Structures, Photoresponse, and Photocatalysis

Abstract

Five cluster polymers based on heterometal-doped titaniumoxide cluster (TOC) monomers are reported. The monomers feature Ti 10 -oxide cluster cores and are connected to the divalent closed-shell heterometal anchors by salicylate ligands. The Sr 2+ , Ba 2+ , and Pb 2+ dopants cause the monomers to bind head-to-head and generate linear chains, while the Ca 2+ and Cd 2+ lead to head-to-tail connections and zigzag chains. The cluster polymers are responsive to visible-light up to 565 nm and photo-catalytically active in both H 2 evolution and CO 2 /epoxide cycloaddition reactions. The photo-absorption, photo-charge separation, and photocatalytic properties of the cluster polymers are dependent on the heterometal dopants in order Cd > Pb > Ba > Sr > Ca. Heterometals serve as the catalytic sites in the cluster polymers, which depending on the contribution of the pCB bottom, facilitate photo-charge separation and interfacial charge transfer, further enhancing catalytic activity. The tunable compositions and topologies of the cluster polymers shown herein may inspire the design and synthesis of more multidimensional functional metal-oxide cluster materials for a variety of applications in the future.

Enhancing the photocatalytic performance of a rutile unit featuring a titanium-oxide cluster by Pb2+ doping

“…To investigate the roles of the active species responsible for RhB degradation, the effects of ascorbic acid (AA, an h + quencher), ispropanol (HO i Pr, an ˙OH quencher), superoxide dismutase (SOD, an O 2 ˙ − quencher), 1,4-diazabicyclo[2.2.2]-octane (DABCO, a 1 O 2 quencher) on the photocatalytic degradation of RhB were investigated. 43–45 For the Ti 12 Pb 2 system, AA and HO i Pr substantially retarded the degradation, while DABCO and SOD had no effect. Therefore, h + and O 2 ˙ − were the active species.…”

“…The photocatalytic degradation of dyes is typically used for evaluating the potential of photocatalysts in water remediation. 36,41–43 Here, Ti 12 Pb 2 and Ti 14 were used in the degradation of a representative dye pollutant, rhodamine B. 13,44 The adsorption/desorption experiments in the dark revealed that both clusters hardly adsorbed RhB.…”

“…The positive slopes of the Mott-Schottky plots indicate that Ti 12 Pb 2 is an n-type semiconductor. 26,27 Hence, the pseudo conduction band (pCB) potential of Ti 12 Pb 2 should be −0.62 V (Fig. 3C), ca.…”

Metal Clusters Based Multifunctional Materials for Solar Cells

“…They allow researchers to construct atomic structure models that are specifically designed to enhance the performance of solar cells. Innovative structural design strategies, demonstrate the potential of metal clusters in optimizing the efficiency and stability of solar cells [130] . Metal‐cluster sensitized solar cells utilize metal clusters as photosensitizers to enhance the light absorption and charge separation capacity of solar cells.…”

“…Innovative structural design strategies, demonstrate the potential of metal clusters in optimizing the efficiency and stability of solar cells. [130] Metalcluster sensitized solar cells utilize metal clusters as photosensitizers to enhance the light absorption and charge separation capacity of solar cells. This results in an improvement in the efficiency and performance of the solar cells.…”