K-doped g-C3N4 decorated with Ti3C2 for efficient photocatalytic H2O2 production

Hydrogen peroxide (H2O2) is an important chemical widely used in the chemical industry. However, the current technical methods of producing H2O2 are limited by high cost, excessive energy consumption and environmental impact. Here, we construct Ti3C2 to modify K-doped g-C3N4 heterojunctions for the production of H2O2. Through the pretreatment of K-doped g-C3N4 and the electrostatic self-assembly method, Ti3C2 is closely bonded to effectively adjust the band position, resulting in a good synergistic effect and an excellent photogenerated electron transfer ability. The construction of this structure has improved the yield of H2O2 and the production of H2O2 under visible light illumination reached as high as 3401 mu mol L-1, which is much higher than that of g-C3N4. In addition, the photocatalytic mechanism shows that the two-step single-electron reduction of O-2 is the main reaction step of H2O2 production. The improvement of photocatalytic performance can be attributed to the doping of K and the construction of the heterojunction, which not only expands the absorption range of visible light, but also inhibits the recombination of photogenerated electron-hole pairs and accelerates carrier separation. At the same time, the catalyst has good stability and can be recycled. This work provides a deep understanding of the modification of g-C3N4 and a new strategy for the development of high-efficiency H2O2-producing photocatalysts.