Efficient Visible-Light Photocatalytic Cycloaddition of CO₂ and Propylene Oxide Using Reduced Graphene Oxide Supported BiNbO₄

Abstract

In this study, a series of novel BiNbO 4 and BiNbO 4 /reduced graphene oxide (BiNbO 4 /r-GO) visible-light photocatalysts were prepared. Pure BiNbO 4 was prepared by simple co-precipitation; on the other hand, BiNbO 4 /r-GO composites were prepared by simple mechanical mixing, followed by hydrothermal treatment. The effect of r-GO on the structural, surface morphological, and optical properties of the prepared photocatalysts was investigated using ultraviolet−visible (UV−vis) diffuse reflectance spectroscopy (UV−vis DRS), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and Brunauer−Emmett−Teller (BET) for the determination of the specific surface area and porosity and energy-dispersive X-ray spectroscopy (EDX) for determining the elemental composition. A red shift in optical band gap measurements was observed with the increasing r-GO mass percentage in the prepared BiNbO 4 /r-GO composites. Photocatalytic activities of pure BiNbO 4 and the composites were evaluated using the photocatalytic cycloaddition of carbon dioxide to propylene oxide as a model reaction. All the prepared photocatalysts produced cyclic propylene carbonate selectively with no polymeric material observed. The highest photocatalytic efficiency was achieved using BiNbO 4 /5% r-GO composite photocatalyst, where the mass percentage of r-GO was 5%.

Atomically Dispersed High‐Density Al–N4 Sites in Porous Carbon for Efficient Photodriven CO2 Cycloaddition

“…have been developed for photocatalytic CO 2 cycloaddition reaction. [ 6,64–66 ] It is believed that photogenerated electrons are used to convert absorbed CO 2 into radical anion (CO 2 •− ). However, the formation of CO 2 •− from CO 2 photoreduction need a very negative equilibrium potential of 1.9 V versus NHE (normal hydrogen electrode), [ 67 ] which imposes strict requirements for the photocatalysts.…”

Graphitic Carbon Nitride Modified with Zr-Thiamine Complex for Efficient Photocatalytic CO2 Insertion to Epoxide: Comparison with Traditional Thermal Catalysis

“…The epoxide is efficiently activated by the photogenerated hole and transforms into Zr-activated epoxide radical cation. Similarly, photogenerated electrons at the conduction band can activate the CO 2 and form CO 2 ̇ radical . The tendency for radical formation is higher if the conduction band is situated at a more negative potential .…”

“…However, the most sustainable process is the photocatalytic activation of CO 2 . Only a few reports are available for photoassisted CO 2 insertion into epoxide to produce cyclic carbonate. , These photocatalytic reactions are conducted in the presence of a suitable cocatalyst.…”

An Earth-abundant cobalt based photocatalyst: visible light induced direct (het)arene C–H arylation and CO2 capture

“…process of ring-opening of the epoxide cation radical which upon coupling with the CO 2 radical anion yields the corresponding cyclic carbonate. 19,62,[67][68][69][70] Catalytic reusability test Furthermore, to validate the practicality and utility of the Co@Apz@ASMNP catalyst for the model C-H arylation reaction, a recyclability test was conducted by using PhN 2 BF 4 and benzene as the model substrate under the optimized reaction conditions. Upon the completion of the reaction, Co@Apz@ASMNPs were collected via an external magnet, washed with absolute ethanol overnight, dried under vacuum and subjected to the subsequent run.…”