Engineering rationally-designed Ta3N5-CoO heterojunction nanofibers for dramatically enhanced photocatalytic CO2 reduction

Abstract

Photocatalytic reduction of CO₂ into valuable carbon-based products using solar energy is a promising strategy to address the global energy crisis and mitigate the greenhouse effect. In this study, we present a rationally-designed Ta₃N₅-CoO nanocomposites for highly-efficient CO production. The porous Ta₃N₅ nanofibers are fabricated by electrospinning, and the heterojunctions are constructed by precisely depositing CoO nanoparticles onto Ta₃N₅ nanofibers by atomic layer deposition (ALD), respectively. The resultant heterostructures not only improve the CO₂ adsorption capacity, but also facilitate the photogenerated charge separation. Furthermore, the introduced CoO nanoparticles could act as active catalytic sites, thus enhancing the photocatalytic CO₂ reduction kinetics and lowering the reaction energy barrier. As a result, the as-fabricated Ta₃N₅-CoO heterojunctions exhibit a remarkable CO production rate of 8.66 μmol·g⁻¹·h⁻¹, nearly 4 times higher than that of pure Ta₃N₅ porous nanofibers. The superior performance is primarily attributed to the unique nanofiber structure, the synergistic effect of the Ta₃N₅-CoO heterojunction, and the catalytic activity of CoO. This work offers some insights into the development of advanced Ta₃N₅-based photocatalysts toward efficient solar-driven CO₂ reduction.