Novel LaFeO/AgCO nanocomposites are synthesized by co-precipitation method for photocatalytic degradation of Rhodamine B (RhB) and -chlorophenol under visible light irradiation. Heterostructures between LaFeO and AgCO semiconductors are formed during the synthesis of these nanocomposites. Among the nanocomposites prepared with different ratios of LaFeO and AgCO, 1% LaFeO/AgCO shows the highest photocatalytic activity for the degradation of RhB. Maximum electron-hole pair decoupling efficiency is observed in 1% LaFeO/AgCO, which causes the greater activity of the heterostructure. Degradation efficiency of 99.5% for RhB and 59% for -chlorophenol has been obtained under natural sunlight within 45 min. Interestingly, the stability of AgCO is improved dramatically after making nanocomposite, and no decomposition of the catalyst was observed even after several photocatalytic cycles. Reactive oxygen species scavenging experiments with -benzoquinone, isopropyl alcohol, and ammonium oxalate suggest that a major degradation process is caused by holes. Degradation of RhB into small organic moieties is detected using LC-MS technique. Further, the efficient mineralization of the degradation products occurs during the catalytic process.