Cu-doped TiO2 nanofibers coated with 1T MoSe2 nanosheets providing a conductive pathway for the electron separation in CO2 photoreduction

• Published in: Applied surface science Vol. 636; p. 157832
• Main Authors: Khan, Haritham, Pawar, Rajendra C., Charles, Hazina, Sunyong Lee, Caroline
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2023
• Subjects: 1T MoSe2; CO2 photoreduction; Cu-doped TiO2 NFs; S-Scheme; UV–vis light irradiation; 1T MoSe2; UV–vis light irradiation; CO2 photoreduction; Cu-doped TiO2 NFs; S-Scheme
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2023.157832

[Display omitted] •Cu-TiO2 NFs/MoSe2 heterojunctions were fabricated through the solvothermal method for the UV–vis light active photocatalytic CO2 reduction.•Integration of copper coupled with a highly conductive phase of 1 T MoSe2 (80%) accelerated the separation and migration of photogenerated carriers.•Reaction intermediates are directly detected and analyzed by in-situ FTIR spectra.•A 2 wt% MoSe2 loaded on one-dimensional Cu-doped TiO2 showed the highest CO2 photoreduction activity (H2; 81 µmol/g, CO; 396 µmol/g, and CH4; 92 µmol/g) with CO2 selectivity of 90%.•A possible S-scheme mechanism for CO2 photoreduction over Cu-TiO2 NFs/MoSe2 was proposed. Efficient solar-driven conversion of CO2 into valuable chemical energy offers a promising way to address the issues of energy shortage and climate change. However, the weak and slow charge kinetics severely impede CO2 photoreduction. Herein, hybrid-phase MoSe2(1 T-2H MoSe2) nanosheet-coated Cu-doped TiO2 nanofibers (Cu-TiO2 NFs) were prepared using a solvothermal method. Different characterizations confirmed the successful doping of Cu into a TiO2 crystal lattice and the generation of stable 1 T-2H MoSe2 in the composite samples. The developed internal electric field drives electrons from the Cu-TiO2 NFs to MoSe2, demonstrating the presence of a Step-scheme (S-scheme) charge transfer path in the Cu-TiO2 NFs/1T-2H MoSe2 heterostructure, which allows efficient and selective CO2 photoreduction. In addition, the optimum sample contains an abundant 1 T MoSe2 coupled with Cu+/Cu0 which offers copious active sites to improve CO2 adsorption and subsequent conversion to CO and CH4. The optimum sample exhibits a remarkable CO2 selectivity of 90%. These findings provide new possibilities for improving the preparation of efficient photocatalysts for the photoreduction of CO2.