Atomically dispersed scandium Lewis acid sites on carbon nitride for efficient photocatalytic hydrogen peroxide production

Photocatalytic reduction of oxygen represents a promising way to produce hydrogen peroxide (H 2 O 2 ) owing to the merits of energy saving and environmental benignancy. However, the low activity and selectivity of the photocatalyst impede its practical application. Herein, following the principle of metal ion-coupled electron transfer, we have fabricated a class of graphitic carbon nitride (g-C 3 N 4 ) decorated with atomically dispersed scandium Lewis acid (Sc/H-CN) using a facile impregnation-calcination method. The as-synthesized Sc/H-CN exhibits excellent H 2 O 2 production performance with a rate of 55 µmol h −1 , which is 6.2 times over bare CN. The improved performance is ascribed to the enhancement of O 2 electron-accepting capability through binding of Sc Lewis acid sites with intermediate ·O 2 − , inhibiting its reverse reaction. Moreover, density function theory (DFT) calculation and Koutecky-Levich analysis show that the reduced O−O bond breakage is responsible for the high selectivity in the production of H 2 O 2 . This work provides a new strategy for the design of photocatalysts equipped with appropriate active sites towards various applications.