Nonmetallic surface plasmon resonance coupling with pyroelectric effect for enhanced near-infrared-driven CO2 reduction

Plasmonic semiconductors with both features of metals and semiconductors are expected materials for solar light harvesting. Here, plasmonic semiconductor heterostructures were constructed by coupling pyroelectric black phosphorus (BP) and plasmonic tungsten oxides (WO) as photocatalyst for CO2 reduction. Intriguingly, under visible and near-infrared (NIR) light irradiation, the plasmonic BP/WO heterostructures with optimal composition exhibit high-selective 26.1 μmol g-1h−1 CO generation (98 %), which is 7- and 17-fold higher than those of plasmonic WO and pyroelectric BP, respectively. The interface bonds (P-O-W) were detected by FTIR spectra and demonstrated by density functional theory (DFT) calculations as dominant channels for electron transfer from BP to WO. Plasmonic thermal effect of WO can increase the local temperature to 86 °C under visible and NIR light irradiation, triggering pyroelectric effect of BP and generating pyroelectric carriers, which enhance the electron transfer from BP to WO. Therefore, continuous electron injection from pyroelectric BP to WO enhances surface plasmon resonance for high-selective CO2 reduction. This work provides clear proofs to demonstrate that constructing pyroelectric effect on plasmonic heterostructures is one useful strategy to promote NIR-harvesting for artificial photosynthesis.