Synergistic effect stemming from vertically anchored seamless 2D MoSe2 nanosheets on 1D NiTiO3 nanofibers toward CO2 photoreduction

Abstract

Herein, nickel titanate nanofiber/molybdenum diselenide nanosheet (NiTiO3 NF/MoSe2) heterostructures were prepared and their photocatalytic CO2 photoreduction performance was assessed. The heterostructures were synthesized via a facile two-step synthesis route combining an electrospinning technique followed by a solvothermal method. The MoSe2 nanosheets were vertically anchored to the surface of NiTiO3 NF, thereby increasing the number of exposed active edges that are pivotal to photocatalytic performance. By tuning the loading of MoSe2 in the heterostructure, the optimal condition was obtained for the fabrication of the NiTiO3 NF/MoSe2 heterojunctions. The as-prepared heterojunctions exhibited higher photocatalytic activity than pure NiTiO3 NF and MoSe2 for the photocatalytic reduction of CO2 under ultraviolet-visible light irradiation. Among the several hybrid samples, the optimal sample displayed a 6.6- and 7.7-fold enhanced production of CO (386 µmol g–1) compared with that of pure NiTiO3 NF (58 µmol g–1) and pure MoSe2 (50 µmol g–1), respectively, with overall CO2 selectivity of 86%. This enhanced photocatalytic activity was attributed to synergy created by tailored loading of MoSe2 nanosheets onto the 1D NiTiO3 NF. This hierarchical growth of MoSe2 over NiTiO3 NF provided more exposed edge sites, enhanced light absorption over the entire spectrum, and improved separation of photogenerated electrons and holes at the NiTiO3 NF/MoSe2 heterojunction interface. Such NiTiO3 NF/MoSe2 heterojunctions with broad spectral photocatalytic performance have potential applications in water splitting and water treatment.