We have intended and preparation of hierarchically absorbent materials were covered with a NiMn2O4 and acts as a catalyst for azo dye degradation. The polyaromatic-based (PA) absorbent compounds were initially constructed by bromomethylated aromatic hydrocarbons which undergo self-polymerization in presence of ZnBr as a reagent and cross linker is bromomethyl methyl ether. The absorbent black materials with a 3D network were prepared by direct carbonization and activation of the as-prepared PA. The hydrothermal method was adapted for the preparation of carbon hybrid material C@NiMn2O4 powder's catalytic activity is effective in reducing p-nitrophenol to p-aminophenol and decolorizing carbon-based dyes like methyl orange (MO), methyl yellow (MY), and Congo red (CR) in aqueous media at 25 °C when NaBH4 is added. UV–visible spectroscopy was used to analyze the dyes' breakdown at regular interval.

Hierarchically porous polyaromatic carbon spheres decorated NiMn2O4 nanocomposite: efficient selective azo dye degradation from aqueous water and reduction of p-nitrophenol to p-aminophenol
    Abstract
    1 Introduction
    2 Experimental methods
        2.1 Materials
        2.2 Preparation of C@NiMn2O4 mixture
        2.3 Common method for the decrease of organic dyes
        2.4 Catalytic reduction of dyes
        2.5 Typical protocol for p-nitrophenol reduction
    3 Results and discussion
        3.1 Catalytic PNP reduction
    4 Conclusions
    Acknowledgements 
    References

• Reddi Mohan Naidu Kalla(School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea)
• T. Kaliraja(Department of Electronics and Communication Engineering, Srivenkateswara College of Engineering, Tirupati, Andhra Pradesh, India)
• Sivarama Krishna Lakkaboyana(Department of Chemistry, Vel Tech Rangarajan Dr. Sagunthala R&D Institute of Science and Technology, Avadi, Chennai 600062, Tamil Nadu, India)
• Seong‑Cheol Kim(School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea)
• Il Kim(School of Chemical Engineering, Pusan National University, Busandaehag‑ro 63‑2, Geumjeong‑gu, Busan 46241, Republic of Korea)