LAUSR

Abstract H 2 O 2 is produced industrially by the anthraquinone method, in which energy consumption is high because of its multistep hydrogenation and oxidation reactions. In this work, hollow copper-doped graphitic carbon nitride (g-C 3 N 4 ) microspheres with outstanding photocatalytic H 2 O 2 production ability are prepared. The characterization results demonstrate that Cu + is not present as the oxide but instead inserts at the interstitial position through coordinative Cu(I)-N bonds. These Cu(I)-N active sites can act as chemical adsorption sites to activate molecular O 2 . Moreover, as an “electron transfer bridge”, Cu(I)-N active sites promote electron transfer from the catalyst to the adsorbed O 2 molecules. The as-prepared copper-doped g-C 3 N 4 displays much higher H 2 O 2 equilibrium concentration and formation rate than neat g-C 3 N 4 prepared by calcination does, as well as excellent structural stability. Density functional theory simulations show that Cu(I)-N active sites can adsorb the O 2 molecules with high adsorption energy and elongate the O O bond. Charge density difference results confirm the electron transfer from the Cu + doping sites to the O 2 molecules. The Mulliken charge is −0.51 when the O 2 adsorbed on Cu + doping sites. This electron-rich environment is beneficial to the H + attack to form H 2 O 2 .