Evident improvement of nitrogen-doped graphene on visible light photocatalytic activity of N-TiO2/N-graphene nanocomposites

Nanocomposites N-TiO2/N-graphene (NTNG) are synthesized through the separate N-doping of titanium dioxide and graphene oxide avoiding the potential redoping of N-TiO2 with the aim clearly to investigate the individual N-doping effect of graphene oxide in NTNG on the photodegradation performance. The as-prepared nanocomposites are respectively characterized by XPS, IR, UV–vis diffused reflectance, XRD and TEM. The XPS results revealed the successful N-doping of TiO2 and graphene oxide. The visible light photodegradation performance of NTNG is higher than that of NTG. The fitted apparent first-order kinetics rate constant ka obviously indicated that the N-doping of graphene oxide in NTNG causes the 2.4-times increase of photodegradation activity compared with that of N-TiO2/graphene oxide (NTG) while the introduction of N-graphene totally results in the 5.5-times increase compared to that of N-TiO2 nanoparticles.