Rare earth and transition metal co-doped LaFeO3 perovskite and its CNTs reinforced nanohybrid for environmental remediation application

Abstract

Herein, rare earth (Gd) and transition metal (Co) co-doped LaFeO3 [La1-xGdxFe1-yCoyO3, (x = 0.08, y = 0.05), LGFCO] perovskite and its carbon nanotube (CNT) reinforced nanohybrid (LGFCO@C) were prepared for the first time via a wet-chemical and post-ultrasonication method. The well-known physical and electronic studies, i.e., XRD, Raman, FTIR, and EDX, were carried out to confirm the doping and CNT reinforcement. The effects of adopted co-doping and reinforcing approaches on the morphology, surface area, conductivity, and band structure were also investigated via SEM, BET, I–V, and UV–vis studies. Due to its hybrid composition, adequate band gap (2.37 eV), greater surface area (105.6 m2 g−1), and superior electronic conductivity (4.432 × 10−1 Scm−1), the LGFCO@C catalyst has remarkable catalytic capabilities for the mineralization of the anionic dye phenol red (PR). Apart from doping, the CNTs reinforced with LGFCO perovskites greatly improved the nano-hybrid's light harvesting and catalytic activity. After only 1 h of exposure to solar radiation, LGFCO@C mineralized 91.6% PR dye with a constant rate value of 0.04 sec−1. A dose of 20 mg of LGFCO@C effectively mineralizes the PR dye in acidic media (pH = 3), according to an optimization study. Furthermore, scavenging tests validate that photo-generated electrons, holes, superoxide, and hydroxyl radicals form during the photocatalytic reaction and play their role in the PR dye mineralization process. The stability and reusability of the LGFCO@C catalyst were also evaluated for five cycles. Even after five successful reusability tests, the LGFCO@C catalyst lost only 11.4% of its activity. Our study indicates that integrating the maximum number of features into a single catalyst is a promising strategy and can open a new avenue in the field of photocatalysis.