The synthesis of the P/N-type NdCoO3/g-C3N4 nano-heterojunction as a high-performance photocatalyst for the enhanced photocatalytic degradation of pollutants under visible-light irradiation

Abstract

The treatment of industrial and domestic colored effluents and the use of photocatalysts have today attracted much attention among researchers. With the varied photocatalytic materials, the ones with narrow bandgap are thus of greater significance thanks to their acceptable performance in optical fields. The other obvious property of such materials is their lower costs because a large part of sunlight is in the visible region. In this work, the bare perovskite-type neodymium cobaltite and neodymium cobaltite/graphite carbon nitride (p/n-type NdCoO3/g-C3N4) was synthesized using sol-gel auto combustion. Different reductants were also employed during this fabrication for morphological engineerings, such as glucose (carbohydrate), L-valine (amino acid), and citric acid. As well, X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), and energy-dispersive X-ray spectroscopy (EDS) were utilized to prove the purity of the specimens, and then transmission electron microscopy (TEM) and field-emission scanning electron microscopy (FE-SEM) were applied to explore their morphology. The various properties of the product, such as the optical, magnetic, porosity, and surface features, were correspondingly checked by diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy, vibrating-sample magnetometry (VSM), and Brunauer-Emmett-Teller (BET) surface area analysis, respectively. Citric acid was thus selected as an optimal fuel because of the formation of finer particles and morphology. In addition, the NdCoO3 nanoparticles (NPs) were exploited as a catalyst for the degradation of anionic dyes (viz. erythrosine [Red No. 3], methyl orange [MO], and eriochrome black T [EBT]) and cationic ones (i.e., rhodamine B [RhB], acid red 14 [ACR14], and acid yellow 23 [AY23]) under visible-light irradiation. The study findings accordingly revealed that the heterostructures emerged at the interfaces between the p-type NdCoO3 and n-type g-C3N4, leading to the EBT decolorization, reached 95.8% after 120 min, and were higher than the photodegradation of the pristine NdCoO3 and g-C3N4.