Constructing Pd/ferroelectric Bi4Ti3O12 nanoflake interfaces for O2 activation and boosting NO photo-oxidation

Photo-oxidative NOx removal often encountered with sluggish charge carrier separation kinetics and poor selectivity. Herein, Pd/ferroelectric Bi4Ti3O12 nanoflakes (Pd/BTO NF) were constructed to investigate the photo-excited charge separation, O2 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/TiO2. Revealed by electronic paramagnetic resonance and radical scavenging tests, it is observed that the primary O2 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 O2 activation species, and notable selectivity changes in photocatalysis mediated environmental remediation reactions.

Automated summary

In this study, Pd/ferroelectric Bi4Ti3O12 nanoflakes were constructed to investigate the mechanisms of photo-excited charge separation and O2 activation in NOx removal. Results showed that the ferroelectric BTO NF significantly promoted bulk charge separation and led to boosted NO removal kinetics compared to traditional Pd/TiO2 photocatalysts. Different metal/ferroelectric interfaces were found to generate varying O2 activation species, resulting in notable changes in selectivity in environmental remediation reactions.