In the present work, LaFeO3 perovskite was prepared via ultrasonic probe with power of 60 W and frequency of 18 KHz. LaFeO3 nanorods were formed when sonication time was 20 min. In this research, green materials including corn, starch, and rice were used to control the size, morphology, and purity of final products. As-prepared LaFeO3 nanostructures were used to purify water containing organic contaminants. LaFeO3 nanostructures prepared by using corn, starch, and rice showed higher photocatalytic activity compare to LaFeO3 nanostructures without natural capping agents. Using corn increased degradation efficiency by 65% under visible light. XRD results show that Fe2O3 appeared as an impurity when starch was used to prepare LaFeO3 nanostructures. This impurity significantly boosts the degradation efficiency under UV light. Fe2O3 under UV light act as co-absorbent and boost efficiency by 43%. LaFeO3 nanostructures were characterized by XRD, EDX, SEM, CV, BET, TEM, DRS and FT-IR.