Vacancy engineering of AuCu cocatalysts for improving the photocatalytic conversion of CO₂ to CH₄

Abstract

Vacancy engineering has been performed on AuCu cocatalysts for enhanced photocatalytic CO2-to-CH4 conversion through tailoring the electron structure and surface configuration simultaneously.

Enhanced Charge Separation in NiO and Pd Co-Modified TiO2 Photocatalysts for Efficient and Selective Photoreduction of CO2

“…According to the literature works, two peaks at 530 and 531.5 eV could be attributed to the lattice oxygen (O L ) and the hydroxyl group (O H ) on the surface of TiO 2 . 32 O H /O L molar ratio for TiO 2 and NiO/TiO 2 photocatalysts were found to be 0.30 and 0.37. The corresponding CO 2 adsorption for these catalysts was found to be 3.17 and 3.29 cm 3 •g −1 (Table 1), which suggested that the introduction of NiO would increase the amount of O H on TiO 2 , and then increase the CO 2 adsorptive capacity.…”

“…However, the surface state of oxygen changed along with the deposition of NiO and Pd. According to the literature works, two peaks at 530 and 531.5 eV could be attributed to the lattice oxygen (O L ) and the hydroxyl group (O H ) on the surface of TiO 2 . O H /O L molar ratio for TiO 2 and NiO/TiO 2 photocatalysts were found to be 0.30 and 0.37.…”

Engineering approach toward catalyst design for solar photocatalytic CO 2 reduction: A critical review

“…A‐C, TEM and HRTEM images of TiO 2 ‐AuCu; D‐F, TEM and HRTEM images of TiO 2 ‐AuCu‐V; G and H, EDX spectra of TiO 2 ‐AuCu and TiO 2 ‐AuCu‐V, respectively; Reproduced with permission 42 . Copyright 2020, Elsevier.…”

“…Apart from metal oxide‐based catalyst, surface vacancy engineering on the metal‐based catalyst is also capable of achieving the activity enhancement of artificial photosynthesis. Bai et al 42 proposed an acid etching treatment of AuCu co‐catalyst to create Cu vacancies for photocatalytic conversion of CO 2 to CH 4 with the activity and selectivity. To confirm the successful introduction of Cu vacancies, characterization methods including transmission electron microscope (TEM), high‐resolution transmission electron microscope (HRTEM), and energy dispersive X‐ray (EDX) are carried out.…”

“…For example, TiO 2 has been considered as one of the most popular semiconductors applied to photocatalysis with prestigious advantages, including easy availability, low toxicity, outstanding chemical stability, and unique optical and electronic properties, and a recently published review on TiO 2 ‐based photocatalysts for CO 2 reduction is available 54 . Nevertheless, because of inefficient solar energy utilization substantiated by the wide bandgap, researchers have employed various methods to improve the activity of such photocatalysts, including metal or non‐metal doping, 40,41,55‐61 alloying, 42,51‐53 facet engineering, 62‐65 nanostructure tailoring, 13,40,46,66,67 surface defect engineering, 43,68,69 and p‐n heterojunction or Z‐scheme system constructing 44,45,47‐50,70‐74 . In general, these methods all aim at either improving the separation efficiency of photogenerated electron/hole pairs, namely prolonging the lifespan of electrons for CO 2 reduction, or creating more catalytically active sites.…”