Internal Electric Field Assisted Photocatalytic Generation\nof Hydrogen Peroxide over BiOCl with HCOOH

Abstract

Hydrogen peroxide\n(H₂O₂) is a superb, clean,\nand versatile reagent. However, large-scale production of H₂O₂ is manufactured through nongreen methods that motivate\npeople to develop more efficient and green technologies as alternatives.\nAs a novel and green technology used for H₂O₂ generation, the efficiency of photocatalysis is still far from satisfactory.\nHere, we demonstrate a novel and efficient path of the generation\nof H₂O₂ in BiOCl photocatalysis but not the\ndirect electron reduction of O₂ or hole oxidation of OH^– to H₂O₂. Super high production\n(685 μmol/h) of H₂O₂ by the addition of\nHCOOH as the hole shuttle was realized over BiOCl nanoplates. In this\nphotocatalytic system, the BiOCl supplied abundant photoinduced holes\nto initiate HCOO^• radical. The HCOO^• further reacts with OH^– to •OH which is\nproven to be the source of the H₂O₂. Apart from\nHCOOH, O₂ also played important roles. The O₂ not only promoted the reaction through the cycle between Bi³⁺ and Bi, which decreased the combination of carriers, but\nalso avoided the carbonation of surfaces, thus achieving the high\nproduction of H₂O₂ (1020 μmol/h). In this\nwork, we shed light on a deep understanding of the photocatalytic\nevolution of H₂O₂ in a novel perspective and\nachieve high production.