Fiber-like ZnO with highly dispersed Pt nanoparticles for enhanced photocatalytic CO2 reduction

Abstract

Utilizing solar energy to convert carbon dioxide (CO2) into chemical fuels could simultaneously mitigate the greenhouse effect and fossil fuel crisis. Herein, a heterogeneous photocatalyst of ZnO nanofiber deposited by Pt nanoparticles was successfully synthesized toward photocatalytic CO2 reduction via radio-frequency thermal plasma and photo-deposition method. The Pt nanoparticles were introduced on the surface of ZnO nanofibers to broaden the light absorption and utilization, increase the additional reaction active sites and facilitate the separation of photo-generated electron/hole pairs. Combined with the natural advantages of short transfer path of charge carriers and self-support effecting in humid reaction environment for nanofibers, the Pt/ZnO hetero-junction nanocomposites displayed superior photocatalytic activity for CO2 reduction with respect to bare ZnO nanofibers, affording a CO-production rate as high as 45.76 μmol g−1 h−1 under 300 W Xe lamp irradiation within a gas–solid reaction system. Furthermore, in-suit Fourier transform infrared (FTIR) spectra were applied to unveil the details during photocatalytic CO2 reduction. This work presents a hetero-junction nanocomposite photocatalyst based on eco-friendly semiconductor and metal materials.