Synergizing Electron and Heat Flows in Photocatalyst for Direct Conversion of Captured CO2

We report a ternary hybrid photocatalyst architecture with tailored interfaces that boost the utilization of solar energy for photochemical CO2 reduction by synergizing electron and heat flows in the photocatalyst. The photocatalyst comprises cobalt phthalocyanine (CoPc) molecules assembled on multiwalled carbon nanotubes (CNTs) that are decorated with nearly monodispersed cadmium sulfide quantum dots (CdS QDs). The CdS QDs absorb visible light and generate electron-hole pairs. The CNTs rapidly transfer the photogenerated electrons from CdS to CoPc. The CoPc molecules then selectively reduce CO2 to CO. The interfacial dynamics and catalytic behavior are clearly revealed by time-resolved and in situ vibrational spectroscopies. In addition to serving as electron highways, the black body property of the CNT component can create local photothermal heating to activate amine-captured CO2, namely carbamates, for direct photochemical conversion without additional energy input.

Automated summary

We present a ternary hybrid photocatalyst architecture that enhances the utilization of solar energy for CO2 reduction by synergizing electron and heat flows. The architecture consists of cobalt phthalocyanine (CoPc) molecules assembled on multiwalled carbon nanotubes (CNTs) decorated with nearly monodispersed cadmium sulfide quantum dots (CdS QDs). The CdS QDs absorb visible light and generate electron-hole pairs, which are rapidly transferred from CdS to CoPc by CNTs. The CoPc molecules selectively reduce CO2 to CO. The interfacial dynamics and catalytic behavior are revealed by time-resolved and in situ vibrational spectroscopies. Additionally, the CNT component can create local photothermal heating to activate amine-captured CO2 for direct photochemical conversion without extra energy input.