Crystal-Facet-Dependent Piezocatalytic Activity of BiFeO<sub>3</sub> Nanosheets for H<sub>2</sub> Evolution and Environmental Remediation
Xiangge Wang, Xiaoxiao Lu, Xiaojing Zhao, Wen‐Jie Chen, Yubin Liu, Xiaoyang Pan, Shijing Liang
Abstract
Reasonable adjustment of the exposed crystal facets has been proven to be an effective strategy to improve the activity of the catalyst. However, the crystal-facet-dependent piezoactivity is rarely investigated. In this work, BiFeO 3 with highly exposed (012) or (110) crystal facets were synthesized by adjusting the volume ratio of solvent and reaction time. Ethylene glycol was used as a structure-directing agent for the synthesis of BiFeO 3 nanosheets (BiFeO 3 –NS) with highly exposed (012) facets. BiFeO 3 –NS shows an obvious higher piezoelectric catalytic hydrogen evolution rate than that of BiFeO 3 nanoparticles (BiFeO 3 –NP) with highly exposed (110) facets. In addition, the rate constant of BiFeO 3 –NS for the piezocatalytic degradation of rhodamine B (RhB) shows a 2-fold increase than that of BiFeO 3 –NP. A variety of controlled experiments have been performed. It is revealed that these two nanomaterials exhibit comparable specific surface areas and adsorption capacity. BiFeO 3 –NS possesses narrowed bandgap as compared to that of BiFeO 3 –NP. The enhanced piezocatalytic activity of BiFeO 3 –NS can be attributed to its built-in electric field, strong carrier mobility, and effective charge separation efficiency. This study provides an alternative perspective for piezoelectric catalysis in surface engineering.