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

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 mu mol center dot g-1 center dot 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.