Metal-induced oxygen vacancies on Bi2WO6 for efficient CO2 photoreduction

Abstract

Semiconductor-based photocatalysis for efficient solar energy conversion is an ideal strategy to tackle the growing global energy and environmental crisis. However, the development of photocatalysis is still limited by problems such as low utilization of visible light, low efficiency of charge transfer and separation, and insufficient reactive sites. Herein, Au nanoparticles (NPs) were deposited on the surface of Bi 2 WO 6 by a one-step reduction method, which simultaneously induced the formation of oxygen vacancies (OVs) on the surface of Bi 2 WO 6 . The OVs concentration is found to be increased with the increase of Au loading. Au NPs and OVs improve the light absorption and facilitate the separation and transport of the photogenerated carriers. In addition, OVs act synergistically with the nearby metal active sites to optimize the adsorption energy of reactants on the catalyst surface, changing the adsorption form of CO 2 molecules on the catalyst surface. The as-synthesized photocatalyst achieved a photocatalytic performance of up to 34.8 μmol g −1 h −1 of CO 2 reduction to CO without sacrificial agent in a gas-solid system, which is 9.4 times higher than that of the pristine Bi 2 WO 6 . This work may further deepen our understanding on the relationship between metal NPs and OVs, and their combined role in photocatalysis.

Modulating oxygen vacancy concentration on Bi4V2O11 nanorods for synergistic photo-driven plastic waste oxidation and CO2 reduction

“…CO 2 -TPD measurements are performed to determine the strength distribution of basic sites on all catalysts. Except for the weak physical adsorption for CO 2 in 50–150 °C, 34,35 the strong chemical adsorption appears at 400–600 °C in Fig. 4b.…”

“…In addition, a sharp peak at higher temperature between 500 and 600 °C is probably attributed to the formed CO 3 2− with Bi 3+ in the CO 2 -TPD spectrum of V O -BiVO-15. 34,35 The quantity of various basic sites is determined by the integral of peak area and displayed in Table S1. † Obviously, V O -BiVO-15 possesses the most basic sites for CO 2 adsorption among the three catalysts owing to the highest concentration of V O s, which are benecial for CO 2 adsorption and activation.…”

Uniform-embeddable-distributed Ni3S2 cocatalyst inside and outside a sheet-like ZnIn2S4 photocatalyst for boosting photocatalytic hydrogen evolution

“…5i, UEDNiS/ZIS exhibited a much higher intensity related to the CO 2 -TPD peak in the 200-300 range in contrast with ZIS, suggesting the introduction of more alkaline sites accompanied by the formation of the uniform-embeddabledistributed Ni 3 S 2 cocatalyst, leading to the improvement of the photocatalytic H 2 -generation activity. [51][52][53][54]…”

Organic polymer facilitated CO2 photoreduction: a minireview

“…Various catalytic materials, such as metal complexes, 8,9 typical semiconductors (TiO 2 , CdS, ZnTe, ZnS, Bi 2 MoO 6 , Bi 2 WO 6 , etc. ), [10][11][12][13][14][15][16][17] inorganic perovskite halides, 18 mxenes, 19 and metal-organic frameworks, 20,21 have been successfully used as catalysts for CO 2 photoreduction and obtained many breakthroughs. Nevertheless, most of the metal-containing semiconductors reported so far show better photocatalytic performance in the UV light range, which only accounts for five percent of the spectrum.…”