In the present work, LaFeO 3 perovskite was prepared via ultrasonic probe with power of 60 W and frequency of 18 KHz. LaFeO 3 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 LaFeO 3 nanostructures were used to purify water containing organic contaminants. LaFeO 3 nanostructures prepared by using corn, starch, and rice showed higher photocatalytic activity compare to LaFeO 3 nanostructures without natural capping agents. Using corn increased degradation efficiency by 65% under visible light. XRD results show that Fe 2 O 3 appeared as an impurity when starch was used to prepare LaFeO 3 nanostructures. This impurity significantly boosts the degradation efficiency under UV light. Fe 2 O 3 under UV light act as co-absorbent and boost efficiency by 43%. LaFeO 3 nanostructures were characterized by XRD, EDX, SEM, CV, BET, TEM, DRS and FT-IR.