Significantly enhanced catalytic performance of solid-state-synthesized Na_0.5Bi_0.5TiO₃ nanoparticles by piezo-phototronic coupling effect

Piezo-photocatalysis has recently been regarded as a promising strategy in energy generation and environmental remediation. Herein, Na_0.5Bi_0.5TiO₃ (NBT) nanoparticles were fabricated by solid-state method and heat-treated at various temperatures. A coupling effect between piezoelectricity and photoexcitation of NBT nanoparticles to enable a high piezo-photocatalytic performance was demonstrated. The NBT nanoparticles heat-treated at 700^oC exhibit an optimum piezo-photocatalytic performance with a degradation rate of 0.078 min⁻¹ for Rhodamine B, which is 4.2 and 7.4 times of the individual photocatalysis and piezocatalysis, respectively. The high piezo-photocatalytic performance is ascribed to the small grain size, narrow band gap, low fluorescence intensity, low charge transfer resistance and large remnant polarization. Moreover, the NBT nanoparticles exhibit a good durability and universality for the piezo-photocatalytic degradation. On the basis of the radical trapping experiment, a possible piezo-photocatalytic mechanism was proposed. The work provides a new insight into piezo-photocatalysis and a new guidance for the design of high-performance catalysts.