Facilely fabrication of the direct Z-scheme heterojunction of NH2-UiO-66 and CeCO3OH for photocatalytic reduction of CO2 to CO and CH4

Abstract

NH2-UiO-66 is recently regarded as a potential photocatalyst for CO2 reduction reaction due to the high CO2 adsorption capacity, high UV–vis light absorption capacity and chemical stability. Aiming to further improve its activity, in this paper, a composite of NH2-UiO-66 and CeCO3OH (NU/CC) was fabricated via an in-situ growth method of NH2-UiO-66 on CeCO3OH. The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electron spin resonance (ESR) characterizations indicated that a direct Z-scheme heterojunction between CeCO3OH and NH2-UiO-66 was formed via the formation of O-Zr-CO32- bond. The CO2 adsorption measurement, UV–vis DRS spectra and photo(electro)chemical measurements indicated that the optimal composite NU/CC-1.6–90 exhibited the higher CO2 adsorption capacity, stronger respond and wider absorption range to UV–vis light, as well as the significantly delayed recombination of photogenerated electron-hole pairs, compared with other control samples. As a result, NU/CC-1.6–90 delivered the obviously enhanced photocatalytic activity of CO2 to both CO and CH4, and the rate of electron consumption reached 152.8 μmol/g h, 5-fold of that of NH2-UiO-66.