▎ 摘　　要

In this manuscript, we demonstrated that black TiO2-x/N-doped graphene quantum dots (BTNG) nanocomposite photocatalysts exhibit extremely high photocatalytic activity while degradating Rhodamine B (RhB) dye and other common organic species (>15 species were tested). The kinetic constant is 0.86min(-1) under the irradiation of simulated sunlight, which is the highest among all the reported values of TiO2 based photocatalysts. The photocurrent intensity can reach 2.7mA cm(-2), indicating the excellent separation efficiency of the electrons and holes. The BTNG photocatalysts can decompose most of organic pollutants in the industrial sewage, with the total organic carbon (TOC) decreasing from 370mg to 57mg under 30 mins sunlight irradiation. The BTNG also has good stability and cycling performance. Possible mechanisms for the high photocatalytic performance of BTNG were proposed and discussed.