Finely dispersed Au nanoparticles on graphitic carbon nitride as highly active photocatalyst for hydrogen peroxide production

In this work, graphitic carbon nitride (g-C 3 N 4 ) supporting finely dispersed Au nanoparticles is developed as a simple and efficient photocatalyst for H 2 O 2 production under visible light irradiation. Au nanoparticle cocatalyst remarkably enhances photocatalytic activity of C 3 N 4 for H 2 O 2 production. Due to the inert nature to catalyze the decomposition of H 2 O 2 , Au/C 3 N 4 also exhibits stable H 2 O 2 evolution rate. It is of great interest that the maximal H 2 O 2 production activity is reached at the loading amount of Au as low as 0.01%, revealing the great catalytic efficacy of highly dispersed Au cocatalyst during the photocatalytic H 2 O 2 synthesis and the possibility to produce concentrated H 2 O 2 using C 3 N 4 with extremely low Au loading amount. The in situ electron spin resonance studies reveal that the H 2 O 2 is produced through direct 2e − oxygen reduction over Au/C 3 N 4 photocatalyst.