Qian Zhang,Yuanyu Shi,Xianjin Shi,Tingting Huang,Shuncheng Lee,Yu Huang,Jun-ji Cao
Photo-oxidative NO x removal often encountered with sluggish charge carrier separation kinetics and poor selectivity. Herein, Pd/ferroelectric Bi 4 Ti 3 O 12 nanoflakes (Pd/BTO NF) were constructed to investigate the photo-excited charge separation, O 2 activation and the generated reactive oxygen species (ROS) in dictating NO removal. Results showed that the depolarization field of ferroelectric BTO NF significantly promoted bulk charge separation, leading to boosted NO removal reaction kinetics (10 times higher) for Pd/BTO NF comparing with Pd/TiO 2 . Revealed by electronic paramagnetic resonance and radical scavenging tests, it is observed that the primary O 2 activation species differed among Pd, Ag and Pt supported BTO NF photocatalysts, which resulted in different selectivity. The underlying mechanism of NO photo-oxidative conversion pathway was studied by in situ diffuse reflectance infrared Fourier transform spectroscopy. This work illustrate that metal/ferroelectric interfaces can be tuned to obtain differing O 2 activation species, and notable selectivity changes in photocatalysis mediated environmental remediation reactions.
The nitrogen-rich ZnO/g-C 3 N 4 composites were prepared and exhibited excellent photocatalytic performance for hydrogen evolution and NO photo-oxidation under visible-light illumination. The obtained nitrogen-rich ZnO/g-C 3 N 4 composite has efficient visible-light utilization and effective separation of photogenerated electron-hole pairs. Experimental data verifies that the photocatalytic activity of ZnO/g-C 3 N 4 composite could be improved by N dopant. NZnOCN1 composite exhibits the highest photocatalytic activity for H 2 evolution and NO removal. The results show that the possible mechanism of the photocatalytic H 2 evolution reaction is the type II mechanism, while the Z-scheme mechanism of nitrogen-rich ZnO/g-C 3 N 4 composite is conducive to NO photo-oxidation.