▎ 摘　　要

In recent years, the development of low-cost and reusable green catalysts to reduce the organic pollutant of 4nitrophenol (4-NP) into the utilizable intermediate of 4-aminophenol (4-AP) had attracted more and more attention. Herein, we reported a facile strategy to synthesize 3D N-doped graphene/bismuth (NGR/Bi) composites with efficient catalytic properties for 4-NP reduction. TGA exhibited NGR/8Bi catalyst came close to reach the maximum load of Bi (weight ratio 67%). NGR/8Bi catalyst had an apparent rate constant of 0.595 min- 1. After 8 min of catalytic reaction, the conversion of 4-NP reached 99.15%. Doped N facilitated the uniform distribution of Bi on graphene and improved the specific surface area and porosity of the catalyst, all of which contributed to the improvement of catalytic performance. The good reusability was attributed to that the microstructure of catalyst had not been changed significantly after used. The 3D network similar to aerogel made NGR/8Bi very easy to recycle and reuse. EPR spectra showed that H* active free radical was responsible for the conversion of 4-NP. This work revealed that the total surface area of metal particles in metal catalyst composites could affect catalytic performance essentially due to the surface plasma resonance effect.