Simple synthesis of NiCo2O4@rGO nanocomposites for conversion of nitrobenzene via its photoreduction to aniline using visible light

Not only photocatalysis could be widely applied for the elimination of many hazardous species but also it could be applied to produce favorable products from these hazardous compounds. One of the most applicable examples to describe such processes is the production of aniline (as an example of favorable material) from nitrobenzene (as an example of hazardous material) through photocatalytic reaction. In this context; NiCo2O4 nano particles (NPs), prepared via a sol-gel routine, were supported by reduced garphane oxide (rGO) to formulate novel NiCo2O4@rGO heterojunctions. Enhamced optoelectronic, optical and structural characteristics have been attained over the constructed heterojunction. Band gap energy of NiCo2O4 (3.08 eV) was suppressed to 2.34 eV owing to its supporting with 15 wt.% rGO bringing about upgraded absorption of visible light. The constructed nanocomposite was administered effectively for the production of aniline from nitrobenzene. Evidently, the constructed nanocomposite containing 15 wt.% rGO support (1.5 gL(-1)) was registered as the highly efficient photocatalyst such that it exhibited complete transformation of nitrobenzene to aniline when subjected to visible light for 40 min. The recycled NiCo2O4@rGO displayed such transformation with great performance even after application for five cycles. The incorporation of rGO support to NiCo2O4 NPs participated strongly to the photocatalytic improvement via declining the band gap energy as well as suppressing the recombination between the induced charges. And so, the synthesized nanocomposite could be applied as eco-friendly photocatalyst for important transformation reactions. (C) 2021 The Author(s). Published by Elsevier B.V.