Visible-Photoactive Perovskite Ferroelectric-Driven Self-Powered Gas Detection

Chemiresistive sensing has been regarded as the key monitoring technique, while classic oxide gas detection devices always need an external power supply. In contrast, the bulk photovoltage of photoferroelectric materials could provide a controllable power source, holding a bright future in self-powered gas sensing. Herein, we present a new photoferroelectric ([n-pentylaminium]2[ethylammonium]2Pb3I10, 1), which possesses large spontaneous polarization (∼4.8 μC/cm2) and prominent visible-photoactive behaviors. Emphatically, driven by the bulk photovoltaic effect, 1 enables excellent self-powered sensing responses for NO2 at room temperature, including extremely fast response/recovery speeds (0.15/0.16 min) and high sensitivity (0.03 ppm-1). Such figures of merit are superior to those of typical inorganic systems (e.g., ZnO) using an external power supply. Theoretical calculations and in situ diffuse reflectance infrared Fourier transform spectroscopy measurements confirm the great selectivity of 1 for NO2. As far as we know, this is the first realization of ferroelectricity-driven self-powered gas detection. Our work sheds light on the self-powered sensing systems and provides a promising way to broaden the functionalities of photoferroelectrics.