Photocatalytic and ferromagnetic properties of electrically conducting multifunctional Ni/NiO nanocomposites in amorphous carbon matrix

NiO rich Ni/NiO nanocomposites in amorphous carbon matrix was synthesized using solution combustion method and characterized with XRD, FTIR, Raman, SEM, TEM, SAED and XPS. Presence of amorphous carbon (sp2 hybridized) matrix was confirmed from the Raman spectra since compounds were having ID/IG ratio higher than 1. Electrical conductivity of the NiO rich Ni/NiO increased with temperature which corresponds to semiconductor nature. Thermal activation energy increased with respect to Ni content in NiO rich Ni/NiO nanocomposites. Sample with higher Ni content showed better photodegradation efficiency in methylene blue which was contributed by surface plasmon resonance (SPR) of nickel nanoparticles. Higher value of room temperature magnetic coercivity of NiO rich Ni/NiO nanocomposites were due to less magnetic interactions between the nanoparticles attributed to decrease of Ni content in the sample. Blocking temperature of Ni/NiO nanocomposites was close to room temperature and it exhibited ferromagnetism.