Polarisation tuneable piezo-catalytic activity of Nb-doped PZT with low Curie temperature for efficient CO2 reduction and H2 generation

Abstract

The reduction of CO₂ into useful hydrocarbon chemicals has attracted significant attention in light of the depletion in fossil resources and the global demand for sustainable sources of energy. In this paper, we demonstrate piezo-catalytic electrochemical reduction of CO₂ by exploiting low Curie temperature, T _c ∼ 38 °C, Nb-doped lead zirconate titanate (PZTN) piezoelectric particulates. The large change in spontaneous polarisation of PZTN due to the acoustic pressures from to the application of ultrasound in the vicinity of the T _c creates free charges for CO₂ reduction. The effect of applied acoustic power, particulate agglomeration and the impact of T _c on piezo-catalytic performance are explored. By optimization of the piezo-catalytic effect a promising piezo-catalytic CO₂ reduction rate of 789 μmol g^-1 h^-1 is achieved, which is much larger than the those obtained from pyro-catalytic effects. This efficient and polarisation tunable piezo-catalytic route has potential to promote the development of CO₂ reduction via the utilization of vibrational energy for environmental improvement.