Investigation on the Influence of Sc Ions Doping on the Structure and Performance of Ta3N5 Photocatalyst for Water Oxidation under Visible Light Irradiation

A tantalum nitride (Ta 3 N 5 ) photocatalyst with a bandgap of 2.1 eV and theoretical solar‐to‐hydrogen efficiency of 15.9% is an extremely promising candidate for solar water splitting, but its intrinsic/extrinsic structure properties such as existence of reduced tantalum species render its present performance to be far from theoretical expectation. Herein, an attempt is made to adopt foreign Sc atoms with similar ionic radius to Ta atoms to modulate the structure and photocatalytic property of Ta 3 N 5 . Based on detailed characterizations, the partial lattice substitution of Sc to Ta atoms is revealed to be feasible to well inhibit the formation of defect sites and favor enhancement of charge separation and transfer ability. In addition, the Sc ions doping has an unobvious effect on the morphology and size of Ta 3 N 5 as well as bandgap structure. Resulting from the promoted charge separation caused by Sc doping and promoted surface catalysis caused by loading of the CoO x cocatalyst, the photocatalytic water oxidation activity of Ta 3 N 5 can be promoted by about one order. The results demonstrate the feasibility of the Sc ions doping strategy in improving the structure and performance of Ta 3 N 5 , as is expected to be extended to other systems.