Microemulsion synthesis of Co-Ni co-doped LaCrO 3 perovskite and its nanohybrid with graphene for minerzlaition of toxic organic azo dyes

Abstract

In this research paper, visible light-driven ABO3 type (perovskite) lanthanum chromite (LaCrO3; labeled as LCO) and Co-Ni co-doped lanthanum chromite (La1-xCoxCr1-yNiyO3 (x,y = 0.50); labeled as LCCNO) photocatalyst were synthesized by following a facile microemulsion technique. Later, to fabricate their reduced GO-based (La1-xCoxCr1-yNiyO3/r-GO; labeled as LCCNO/r-GO) nanocomposite: LCCNO nanoparticles were decorated on reduced graphene oxide (r-GO) using ultrasonication method to achieve high degradation of carcinogenic and toxic pollutants from the environment. The as-fabricated nanoparticles (NPs) were subjected to different advanced instrumentations regarding their structural and application analysis. The structural, morphological, specific surface area and elemental analysis were studied by XRD (x-ray diffraction), FT-IR (Fourier Transform-Infrared Spectroscopy), SEM (Scanning Electron Microscopy), BET (Brunauer Emmett Teller) and EDX (Energy Dispersive X-ray), respectively. The optical analysis and current-voltage (I-V) experiment was employed to investigate the impact of Co-Ni ions co-doping and r-GO on the bandgap and conductivity of the fabricated material, respectively. Regarding their environmental application study, the fabricated nanomaterial's photocatalytic activity (PCA) was tested against the photodegradation of crystal violet (CV) dye. LCCNO/r-GO NCs photocatalyst showed maximum CV dye photodegradation efficiency (99.02%; 100 min) as compared to pure LCO (36.44%; 100 min) and co-doped LCCNO (73.74%; 100 min) photocatalysts due to its lower band gap (2.14 eV), higher conductivity (6.4 × 105 Sm-1) and larger surface area (123.7 m2/g). According to PCA study, a dose of 20 mg of LCCNO/r-GO photocatalyst degrades cationic CV dye effectively in basic media (pH–11). Furthermore, scavenging tests were employed to investigate the generation of radical species (.O2 and OH∙) during (PCA) experiments. The structure constancy and reusability of the LCCNO/r-GO photocatalyst was observed for five cycles. It lost 5.71% degradation efficiency against CV dye after five cyclic tests. This research provides new insight into developing high-quality structured photocatalysts for environmental remediation under sunlight irradiations.