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Ferroelectric Oxide Nanocomposites with Trimodal Pore Structure for High Photocatalytic Performance.

ABSTRACT: An effective method to improve the photocatalytic performances of powder catalysts is to use the internal electric field from ferroelectrics to separate photogenerated charge carriers. The design and engineering of a complex hetero-junction with a hierarchical pore structure is highly desirable for the efficient application of ferroelectric materials in photocatalysis. Here, we present a novel strategy using two templates to fabricate PbTiO₃/TiO₂/carbon (PTC) nanocomposites with a tunable microstructure. A hard SiO₂ template combined with an ice template followed by an appropriate pyrolysis procedure introduced trimodal (micro-, meso-, macro-) porosity. The as-prepared PTC nanocomposites with optimal mass ratio exhibited excellent photocatalytic and photoelectrochemical performances. PbTiO₃/TiO₂ annealed at 900 °C (PTC-900) showed a MB degradation rate of 0.21 and 0.021 min^-1 under UV and visible light irradiation, which are, respectively, 7.2 and 3 times those of pure PbTiO₃. The photocurrent density of the composite catalyst is 1.48 mA cm^-2 at the potential of 1.0 V versus saturated calomel electrode, and the rates of hydrogen generation of PTC-900 are as high as 2360 and 9.6 μmol h^-1 g^-1 under UV and visible light irradiation, respectively. More importantly, the simultaneous application of ultrasound-induced mechanical waves further improved the photocatalytic reactivity. This work serves to improve understanding on the design of ferroelectric/piezoelectric photocatalysts with a hierarchical pore structure and also proposes a widely applicable strategy for the fabrication of high-performance micro-nano/nano-nano structures.

SUBMITTER: Xu T

PROVIDER: S-EPMC7770796 | biostudies-literature |

REPOSITORIES: biostudies-literature

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