Production of CH4 and CO on CuxO and NixOy coatings through CO2 photoreduction. Issue 4 (August 2022)

• Record Type: Journal Article
• Authors: Ávila-López, Manuel Alejandro; Tan, Jeannie Z.Y.; Luévano-Hipólito, E.; Torres-Martínez, Leticia M.; Maroto-Valer, M. Mercedes
• Is Part Of: Journal of environmental chemical engineering. Volume 10:Issue 4(2022)
• Publication Date: 2022-08
• Subjects: Photocatalysis -- CO2 reduction -- Solar fuels -- CO2 adsorption -- CuxO -- NixOy; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2022.108199
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: CO2 capture and photocatalytic reduction to hydrocarbons is an interesting yet challenging area that requires photocatalysts with the capability to capture and photoconvert CO2 simultaneously. Furthermore, earth-abundant photocatalysts with high efficiency and product selectivity are essential for commercialization. Thus, two earth-abundant photocatalysts based on copper and nickel oxides were selected to produce solar fuels from CO2 photoreduction. The photocatalysts were immobilized on commercial glass fibers substrates by a facile one-step microwave-hydrothermal method. Cux O (x = 1, 2) and Nix Oy (x = 1, 2 and y = 1, 3) coatings on glass fiber were evaluated as photocatalysts in two different reactors to investigate the selectivity in a continuous reactor and a batch system. Two different light sources were employed: a heterochromatic lamp to simulate part of the solar light in the continuous reactor and a LED visible light in the batch reactor. CuO/Cu2 O photocatalysts exhibited a selective production of CH4 (95 µmol g −1 h −1 ) and CH3 OH (177 µmol g −1 h −1 ) from CO2 photoreduction in the continuous and batch continuous systems, respectively. The superior performance was attributed to the unique rod-shape morphology, the presence of oxygen vacancies, and efficient charge transfer in the CuO/Cu2 O heterostructure with high affinity towards CO2, resulting the formation of mono- and bidentate carbonate species during the CO2 photoreduction reaction. Nix Oy coating with 2D cubic shape produced CO (103 µmol g −1 h −1 ) and HCOOH (4245 µmol g −1 h −1 ), associating with the low CO2 affinity and less efficient charge separation compared to CuO/Cu2 O heterostructure. Graphical Abstract: ga1 Highlights: Cux O and Nix Oy coatings were synthesized by one pot microwave-hydrothermal method. The coatings revealed high stability in the CO2 photoreduction under visible-light. CuO/Cu2 O coating were selective to generate CH4 and CH3 OH in gas and liquid phase. NiO/Ni2 O3 was selective to CO and HCOOH production in gas and liquid phase. The CO2 -affinity and the charge transfer efficiency influenced the product selectivity.