Enhancing the strength of pyroelectric polarization and improving the pyro-PEC performance of In2S3 through vacancy engineering

In 2 S 3 is a promising pyroelectric material and its internal polarization field strength has a significant effect on pyro-PEC catalytic performance. Therefore, effective strategies to enhance the polarization strength of the materials play a crucial role in improving the pyro-PEC performance. Here, sulfur vacancies were introduced by simple treatment of the material with vinylpyrrolidone (PVP) solution to study the effect of sulfur vacancy introduction on the thermoelectrocatalytic properties of In 2 S 3 and the mechanism of action is analyzed. It is shown that the current density of In 2 S 3 photoanode with introduction of sulfur vacancies in the hot and cold cycling field at 1.23 V vs.RHE reaches 1.07 mA∙cm -2 , which is 3.15 times higher than that of bare In 2 S 3 . After the introduction of light, the current density reached a maximum value of 2.29 mA∙cm -2 at 1.23 V vs.RHE. It is shown that the introduction of sulfur vacancies not only changes the distribution of dipole moments between In-S, but also increases the distribution of interfacial charges with enhanced polarization effects. Meanwhile, sulfur vacancies triggered an increase in In 2 S 3 surface defects, which promoted the surface polarization behavior and enhanced the response of the material to temperature changes. This study provides a new idea for coordinated catalysis with thermal-optical-electrical multiple external field coupling.