Water splitting and carbon dioxide reduction over alkaline-earth tantalate photocatalysts loaded with metal oxide cocatalysts. (16th September 2021)

• Record Type: Journal Article
• Authors: Garay-Rodríguez, Luis F.; Yoshida, Hisao; Torres-Martínez, Leticia M.; Juárez-Ramírez, Isaías
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 64(2021)
• Page Start: 32490
• Page End: 32502
• Publication Date: 2021-09-16
• Subjects: Tantalates -- Metal oxide decoration -- Water splitting -- CO2 reduction; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.07.092
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Calcium and strontium tantalates with general formula A2 Ta2 O7 (A = Ca, Sr) were prepared by the solid-state synthesis and evaluated in the photocatalytic water splitting and CO2 reduction. A predominance in the water splitting processes is observed in both materials obtaining competitive yields for H2 and O2 compared to the results reported in the literature. A better performance was observed in the Sr2 Ta2 O7 sample associated with its crystalline structure and morphology (H2 = 807 μmol g −1, O2 = 296 μmol g −1, CO = 5 μmol g −1 for 6 h). Besides, both materials were decorated with Co3 O4 and CuO particles acting as cocatalysts. The presence of these oxides enhanced the evolution of the products considerably due to the efficient charges transport avoiding their recombination, being the Co3 O4 loaded sample the most efficient in both cases. The presence of CuO favored the formation of CO in both tantalate materials; however, their rates are not comparable with the obtained for H2 and O2, being the water-splitting process also predominant with the use of both cocatalysts. Graphical abstract: Image 1 Highlights: Ca and Sr alkaline-earth tantalates were prepared by the solid-state reaction. CuO and Co3 O4 cocatalysts were deposited over tantalates by impregnation. Photocatalytic water splitting and CO2 reduction were performed simultaneously. Higher selectivity to water splitting was observed in all catalysts. Both cocatalysts favored the charge transfer avoiding recombination.