Synthesis and Characterization of Mn3o4/BC Nanocomposite and Its Antimicrobial Activity

Supporting Information

Synthesis and characterization of Mn3O4/BC nanocomposite and its antimicrobial activity

K. Bama and M. Sundrarajan

Advanced Green Chemistry Lab, Department of Industrial Chemistry,

School of Chemical Sciences, Alagappa University, Karaikudi -3, Tamil Nadu, India.

*Corresponding author: Tel: +91 94444 96151

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Figure S1: TGA curve of Mn(NO3)2.4H2O decomposition in nitrogen (heating rate: 10 °C/min-1, air flow: 100 ml cm-3).

Figure S1 shows that Mn(NO3)2.4H2O, start to decompose at 180 °C and the weight loss (82.05 % and 73.13 %) happens in the temperature range 180-250 °C. The weight loss may be ascribed to the decomposition of Mn(NO3)2.4H2O precursor. Three mass loss regimes are observed below 250 °C should come from exothermic dehydration, and nitrate decomposition. The overall mass loss between 50 to 1000 °C amounts to ~73.13 % expected for the formation of MnO2 from decomposition of Mn(NO3)2.4H2O. Upon further heating, promote mass loss around 250 to 550 °C, are associated with exothermic peak, correspond to the formation of Mn2O3 nanoparticles. The weight loss is about 83.55 %, which is close to the theoretical value, corresponding to the formation of Mn3O4 nanoparticles. However, the synthesized Mn3O4 nanoparticles, the weight loss started at 550 °C and ended at 1000 °C Above this result, we concluded single phase Mn3O4 nanoparticles under our synthesis conditions at 600 °C [1].

Figure S2: DSC measurement of manganese nitrate tetrahydrate [Mn(NO3)2.4H2O] precursor.

We observed an exothermic with no corresponding mass change which we attribute to melting of Mn(NO3)2.4H2O precursor. The DSC results for Mn(NO3)2.4H2O showed an additional exothermic peak at 186.6 °C besides the evaporation peak. The curves of melting and crystallization of manganese nitrate tetrahydrate. The peaks are sharp, narrow, and melting starts abruptly exothermic peak at 186.6 °C. The presence of the additional peak was attributed to the melting of Mn(NO3)2.4H2O precursor. The Peak starts at Tonset - 173.2 °C to end peak Tonset - 197.8 °C and area of the peak is 154.7 J/g.

However, the endothermicity appears sufficient to raise the particles temperature such as Mn3O4 nanoparticles can be formed at only 600 °C, rather than the nominal 1000°C from Mn(NO3)2.4H2O precursor [2].

Figure S3: TGA profile of pristine bentonite clay precursor.

The TGA graph of pristine sodium bentonite clay shows that the total weight loss of about 3 % occurs between 50 to 1000 °C. The weight loss between 150 to 750 °C is due to the degradation of organic modifier present in the sodium bentonite clay. The above results we concluded the slight decomposition temperature of pure pristine bentonite clay is found to be above 750 °C. The residue mass and mass change of the sodium bentonite is 96.44% (1000 °C) and 3.56 % respectively [3].

Figure S4: DSC curve of pristine bentonite clay precursor.

The DSC results for pristine bentonite clay showed addition small and narrow exothermic peaks.

Below 1000 °C sodium bentonite clay is not decomposition; it is strong material upto1000 °C [4].

Figure S5: Energy dispersive X-ray spectroscopy of (a) Mn3O4 nanoparticles and (b) Mn3O4/BC composite.

Figure S6: (a) scanning electron microscopy and (b) transmission electron microscopy micrographs of Mn3O4 nanoparticles.

References:

1. Na Li, Zhenfeng Geng, Minhua Cao, Ling Ren, Xinyu Zhao, Bing Liu, Yuan Tian, Changwen Hu, Well-dispersed ultrafine Mn3O4 nanoparticles on graphene as a promising catalyst for the thermal decomposition of ammonium perchlorate, Carbon, 54 (2013) 124- 132.

2. Jitendra Kumar Sharma, Pratibha Srivastava, Sadia Ameen, M. Shaheer Akhtar, Gurdip Singh and Sudha Yadava, Azadirachta Indica Plant-assisted Green Synthesis of Mn3O4 Nanoparticles: Excellent Thermal Catalytic Performance and Chemical Sensing Behavior, Journal of Colloid

3. Arindam Chakrabarty, Siva Ponnupandian, Kinsuk Naskar and Nikhil K. Singha, Nanoclay stabilized Pickering miniemulsion of fluorinated copolymer with improved hydrophobicity via RAFT polymerization, RSC Adv.,6 (2016) 34987-34995.

4. Manish Kumar, S Arun, Pradeep Upadhyaya and G Pugazhenthi,Properties of PMMA/clay nanocomposites prepared using various compatibilizers, International Journal of Mechanical and Materials Engineering, 10:7 (2015) 2-9.