Biotemplated top-down assembly of hybrid Ni nanoparticles/N doping carbon on diatomite for enhanced catalytic reduction of 4-nitrophenol

Biotemplated top-down assembly of hybrid Ni nanoparticles/N doping carbon on diatomite (DE/Ni/N-C) was synthesized and used to catalytically reduce 4-nitrophenol (4-NP) solution in presence of NaBH4. The uniform nickel silicate nanosheets uniformly grown on the diatomite with maintained porous structure, enlarging the specific surface area. The thin polyaniline layer was then controllably coated on the nickel silicate nanosheets. The well-dispersed Ni nanoparticles with mean diameter of 20.3 nm were reduced from nickel silicate nanosheets by carbon from polyaniline pyrolysis process. Meanwhile, the N doping carbon layer was in-situ generated outside of the Ni nanoparticles. In the catalytic reduction of 4-NP reaction, the DE/Ni/N-C-800 exhibited excellent catalytic activity with activity parameter 0.053 mg(-1) s(-1) and stability after ten cycles. The presented results show an enhanced catalytic behavior of the DE/Ni/N-C-800 prepared by the low-cost material and simple controllable process, which indicates their potential for environmental remediation applications.