Photocatalytic CO₂ reduction of amino-functionalized MIL-101(Fe) coupled with reduced graphene oxide under UV–visible light illumination

In this investigation, the CO₂ photoreduction reaction was studied under UV–visible light illumination. For this purpose, MIL-101(Fe), as well as amino-functionalized MIL-101(Fe) (N-MIL(Fe)) metal–organic frameworks (MOFs), were coupled with 15 wt.% reduced graphene oxide sheets. The physicochemical features of synthesized catalysts were evaluated by XRD (X-ray Diffraction), FESEM (field emission scanning electron microscopy), BET (Brunauer–Emmett–Teller), FTIR (Fourier transform infrared spectroscopy), and UV–Vis DRS (ultraviolet–visible diffuse reflectance spectroscopy) techniques. The as-prepared photocatalysts were well-characterized, and the results of photocatalytic CO₂ reduction indicate that N-MIL(Fe)@rGO catalyst demonstrates the highest reduction efficiency of 20.7%. This is in accordance with the characterization results that show the coupled sample had a lower band gap, highest average pore diameter of 27.3 nm, and the highest catalytic activity. Finally, a suitable photocatalytic CO₂ reduction mechanism was proposed for the activity of the hybrid N-MIL(Fe)@rGO sample.