In this work, PMA@NH2-MIL-68(Rh) with a mangosteen spherical structure was successfully synthesized by a hydrothermal method for the photocatalytic reduction of carbon dioxide. The electronic structure and morphology of PMA@NH2-MIL-68(Rh) composites were characterized using Fourier transform infrared spectrometer (FTIR), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS). Results showed that the 0.63% PMA@NH2-MIL-68(Rh) composite achieved the optimal catalytic performance, yielding 387.28 μmol·g−...