In this work, we present a facile and dopant-free approach using a peroxo-titanium complex as a precursor to synthesize TiO2–carbon nanotube (CNT) composites at various CNT loadings, ranging from 0 to 10 wt% (gram CNT per unit gram of TiO2). The photocatalytic activity of as-synthesized composites on CO2 reduction was studied. The as-synthesized composites were characterized by X-ray diffraction (XRD) and UV–visible spectroscopy. XRD analysis revealed that the as-produced TiO2 was a mixture of anatase and rutile phase TiO2. UV–vis spectra showed that the absorption edge of the as-synthesized composites was redshifted and exhibited an improvement in light absorbance as compared with the commercially available anatase TiO2. Among the synthesized TiO2–CNT composites, TiO2–CNT with 5 wt% CNT loading showed the highest photocatalytic activity on CO2 reduction. A possible reaction mechanism for the photoreduction of CO2 was proposed.