Reducing ROS generation and accelerating the photocatalytic degradation rate of PPCPs at neutral pH by doping Fe-N-C to g-C3N4

In this study, we designed and synthesized a 1% Fe-N-C nanotube (FeCNT) doped g-C3N4 (1%FeCNT@C3N4) to reduce the biotoxicity of g-C3N4 by reducing ROS generation and enhance its catalytic efficiency at the same time. The 1%FeCNT@C3N4 can not only effectively reduce the ROS generation at neutral pH but also had an extremely low electron-hole pairs recombination rate, which was attributed to the fact that O2 undergone a fourelectron oxygen reduction reaction (ORR) pathway at the Fe-N-C site. Additionally, the degradation results of tetracycline hydrochloride (TH) and Naproxen (NPX) by 1%FeCNT@C3N4 and g-C3N4 showed that the reaction rate constants of 1%FeCNT@C3N4 (0.0176 +/- 0.0012 min-1 and 0.05045 +/- 0.0010 min-1 for TH and NPX, respectively) were much higher than those of g-C3N4 (0.0098 +/- 0.0004 min-1 and 0.0281 +/- 0.0008 min-1 for TH and NPX, respectively). Moreover, the 1%FeCNT@C3N4 is proved to retain its high catalysis property in surface water.