Synthesis of silica and carbon-based nanomaterials from rice husk ash by ambient fiery and furnace sweltering using a chemical method
Sanjeev K. Sharma, Gaurav Sharma, Abhishek Sharma, Kirti Bhardwaj, Km. Preeti, K. Singh, Anirudh Kumar, Vinod Kumar Pal, Eun Ha Choi, Satendra Pal Singh, Nagendra Kumar Kaushik
Abstract
Silica nanoparticles (n-SiO2), graphene nanosheets (n-Gr) and graphene oxide nanosheets (n-GO) were synthesized from the cost-effective biomass rice husk ash (RHA) by the simple chemical process. The crystallite size and micro-strain of all samples were calculated from XRD-peak profile analysis to be 1.5 - 5.4 nm and 8.11 - 28.64 MPa, respectively. FE-SEM images confirmed SiO2 nanoparticles with clustered spherical shapes and petals form of n-Gr and n-GO named RHA-1, RHA-2, RHA-3, respectively. The symmetric stretching band vibrations Si-O and O-Si-O were detected at 472, and 620 cm−1 in the FTIR spectrum, which confirmed the presence of n-SiO2. Bands at 1067, 1106, 1624 cm−1 are related to C-O stretching vibration, anhydrides C-O stretching and C=C stretching vibration of n-Gr, and n-GO, respectively. The core-level of XPS of C showed the binding energy of C‒C (283.21 eV), (291.11 eV), and O‒C=O (294.11 eV), which augmented the formation of graphene. The ratio of Raman peaks (ID/IG <1) is further confirmed the formation n-Gr of graphitic structure of sp2 carbon.