Inductive effect of charge transfer in ferroelectrics and plasmonic Ag heterojunctions for enhanced CO2 photoreduction

Converting carbon dioxide into fuel and chemicals by utilizing solar energy represents a cutting-edge approach to carbon recovery and energy renewal. The transfer behavior of photogenerated electrons and built-in electric field of photocatalysts greatly affect the efficiency of the photoreduction reaction. Herein, the heterostructures composed of bismuth sodium titanate (BNT) ferroelectrics and silver nanoparticles (Ag NPs) are constructed to promote the photocatalytic CO2 performance. The large spontaneous polarization of BNT optimizes the transfer dynamics of photoinduced electrons and holes and causes energy band bending with strong intrinsic electric field. With the aid of Ag NPs, the BNT@xAg heterojunctions exhibit intensified light absorption due to the phenomenon of localized surface plasmon resonance (LSPR), which extends the visible light absorption spectrum and strengthens charge transfer. The modified catalysts demonstrate improved charge separation capacity and notably prolonged electron lifetime up to 40.95 ns. The synergistic effect of LSPR and intrinsic polarization significantly boosts the photocatalytic efficiency together with ultrahigh CO product selectivity, which is outstanding among the ferroelectric and other representative photocatalysts. This study elucidates the photocatalytic enhancement mechanism of plasmonic Ag decorated BNT and offers an alternative route for the design of efficient catalysts.