One-pot synthesis of octahedral NiSe2 as a co-catalyst for enhanced CO2 photoreduction performance

Abstract

Excessive CO2 concentrations in the atmosphere have a range of adverse effects, including climate change and the rise in sea levels. One approach to mitigate these issues is to utilize artificial photosynthesis, which trans-forms CO2 into valuable fuels. In this study, a unique octahedral nickel selenide (NiSe2) structure supported on one-dimensional (1D) nickel titanate nanofibers (NiTiO3 NFs) was created through a one-pot solvothermal process. The optimized NiTiO3 NFs/NiSe2 nanostructure exhibits exceptional CO2 photoreduction performance across a broader range of the solar spectrum (UV-vis). At a 0.09 wt% NiSe2 concentration, the yields of CH4 and CO were 3.14 and 1.47 times higher, respectively, than those produced by pure NiTiO3 NFs. The exceptional photocatalytic activity can be attributed to the efficient electron extraction and transfer from NiTiO3 NFs to NiSe2, as well as the enhanced light harvesting capacity. Furthermore, the introduction of NiSe2 generates more oxygen vacancies (OV) that can promote the adsorption and activation of CO2 and water, considerably reducing the free energy barrier for COOH* formation and accelerating the reaction kinetics. The results of this study are expected to create new opportunities for synthesizing efficient photocatalysts based on transition metal dichalcogenides that can be utilized in energy conversion applications.