This work focuses on exploring metal–organic frameworks (MOFs) for degradation of gaseous pollutants. We demonstrate that NH₂-MIL-101(Fe) hexagonal micro-spindles, as a new photocatalyst, showed an improved performance for degradation of toluene under visible light irradiation. The structural and optical properties of the as-prepared NH₂-MIL-101(Fe) hexagonal micro-spindles were characterized. Furthermore, the catalytic reaction mechanism has been investigated on the basis of in situ Fourier Transform infrared spectroscopy (FTIR) technology. Meanwhile, some intermediates (benzoic acid) and the final product (CO₂) of the degradation of toluene were also identified.