Activated Single-Phase Ti 4 O 7 Nanosheets with Efficient Use of Precious Metal for Inspired Oxygen Reduction Reaction.

The oxygen reduction reaction (ORR) is central to modern energy storage and conversion technologies for grids such as fuel cells and electrolyzers, but challenges remain due to the lack of reliable, economic, and durable electrocatalysts. Here, we develop single-crystal conductive black titanium (Ti 4 O 7 ) nanosheets (NSs) as a new precious metal carrier based on sacrificial hard templates and ultrasonic-assisted peeling, and deposit Pt clusters on Ti 4 O 7   NSs induced by wetness impregnation under the irradiation of visible light (VI; 650 nm). Pt/Ti 4 O 7   NSs provide Ti 3+ , Pt 2+ , and Pt 0+ continuous active sites for the ORR multielectron process, achieving synergy among them. The assistance of visible light not only makes a more uniform and smaller distribution of Pt nanoclusters, but also strengthens the charge transfer, thereby constructing a strong metal-support interaction interface. VI-Pt/Ti 4 O 7   NSs show superior initial oxidation potential and a mass activity of 1.61 A mg -1 Pt at a E 1/2 =0.91 V, which is nine times higher than that of commercial Pt/C. This work provides an effective strategy for achieving high-value applications of titanium sub-oxides and further explores the enhanced interface in metals Ti n O 2n-1 by light radiation.