Macroscopic Spontaneous Piezopolarization and Oxygen-Vacancy Coupled Robust NaNbO3/FeOOH Heterojunction for
Newmoon Priyadarshini1, Sriram Mansingh1, Kundan Kumar Das1
1Centre for Nanoscience and Nanotechnology, Siksha 'O' Anusandhan (Deemed to be University), Bhubaneswar, Odisha 751030, India.
Abstract:
Prompt recombination of photoproduced charges in bulk and surface of a photocatalyst significantly impedes catalytic efficiency. To address these challenges, FeOOH nanorods (NRs) anchored NaNbO3 (NNO) piezoelectric microcubes (MCs) have been fabricated for ciprofloxacin (CIP) degradation and oxygen evolution through water splitting by coupling macroscopic spontaneous piezoelectric polarization and a built-in electric field. The local electric field induced by surface oxygen vacancies (Ovs) and orientation of FeOOH NRs over NNO MCs afford the polarization electric field a significant boost, driving the quick separation/migration of charge carriers from bulk to the surface. The polarized NNO/FeOOH composite with ample Ovs demonstrates an outstanding piezophotocatalytic CIP degradation of 93% in 1 h, higher than pristine materials (NNO and FeOOH), and a high O2 evolution rate of 1155 μmol h-1. The effect of piezoelectric polarization on the catalytic activity is supplemented by theoretical simulations. This work offers an avenue for selective pollutant remediation and water splitting through the rational design of piezoelectric polarization-mediated heterostructure systems with surface Ovs.
