We developed two-step solution-phase reactions to form hybrid materials of Mn3O4 nanoparticles on reduced graphene oxide (RGO) sheets for lithium ion battery applications. Mn3O4 nanoparticles grown selectively on RGO sheets over free particle growth in solution allowed for the electrically insulating Mn3O4 nanoparticles wired up to a current collector through the underlying conducting graphene network. The Mn3O4 nanoparticles formed on RGO show a high specific capacity up to ~900mAh/g near its theoretical capacity with good rate capability and cycling stability, owing to the intimate interactions between the graphene substrates and the Mn3O4 nanoparticles grown atop. The Mn3O4/RGO hybrid could be a promising candidate material for high-capacity, low-cost, and environmentally friendly anode for lithium ion batteries. Our growth-on-graphene approach should offer a new technique for design and synthesis of battery electrodes based on highly insulating materials.

Mn3O4-Graphene Hybrid as a High Capacity Anode Material for Lithium Ion Batteries

This experimental study deals with the critical heat flux (CHF) of aqua-based reduced graphene oxide (rGO) nanofluids at 0.2 %, 0.6 %, and 0.8 % concentrations. This investigation also interprets the results of different characterization studies of rGO nanofluid namely atomic force microscopy (AFM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), dynamic light scattering (DLS), zeta potential and Branauer–Emmett–Teller (BET) surface area analysis to confirm the existence. Thermal conductivity and dynamic viscosity of the working fluid are measured over a range of temperatures (30–70 °C). From this investigation, it is inferred that the thermal conductivity increases with the increase in temperature while its viscosity gets reduced for both deionized water and rGO nanofluid. The heat transfer coefficient (HTC) augmentation is observed to be 0.9, 1.8, and 2.3 times greater than deionized water corresponding to 0.2 %, 0.6 %, and 0.8 % concentrations of rGO nanofluids. The HTC of the synthesized nanofluid increases with increase in concentration of rGO and its compared than deionized water. The CHF enhancement or deterioration by rGO nanofluids is due to the different volume concentrations including heat transfer surface and their interaction and the nanoparticles suspended in the liquid.

Performance and Characterization Studies of Reduced Graphene Oxides Aqua Nanofluids for a Pool Boiling Surface

Emerging challenges for the agro-industrial food waste utilization: A review on food waste biorefinery.

Recently, aluminium–air batteries have received great attention because of their high specific capacity and low cost. However, corrosion of the aluminium (Al) anode is a critical problem limiting their practical applications. In this study, a decrease in the corrosion and an increase in the discharge performance of the Al anode were demonstrated through the use of nano-yttrium-stabilized zirconium (nano-YSZ). Three weight ratios of nano-YSZ blended with Al were prepared via mechanical stir casting. The surface hardness of the new Al alloys was determined using nano-indentation method and phase transition. Crystallite size measurements were conducted using X-ray diffraction analysis. Subsurface morphologies were conducted using scanning electron microscopy. Corrosion studies were carried out using electrochemical impedance spectroscopy and linear sweep voltammetry. The discharge and short-circuit studies of the prepared Al–air battery were undertaken using different Al alloy anodes. The results demonstrated that the Al anode having a higher ratio of nano-YSZ (5 wt%) had the highest discharge behaviour and excellent corrosion resistance making it a potential candidate as an electrode for the Al–air battery.

A novel nano-YSZ-Al alloy anode for Al–air battery

Abstract Solid wastes from domestic, industrial and agricultural sectors cause acute economic and environmental problems. These issues can be partly solved by anaerobic digestion of wastes, yet this process is incomplete and generates abundant byproducts as digestate. Therefore, cultivating mixotrophic algae on anaerobic digestate appears as a promising solution for nutrient recovery, pollutant removal and biofuel production. Here we review mixotrophic algal cultivation on anaerobic waste digestate with focus on digestate types and characterization, issues of recycling digestate in agriculture, removal of contaminants, and production of biofuels such as biogas, bioethanol, biodiesel and dihydrogen. We also discuss applications in cosmetics and economical aspects. Mixotrophic algal cultivation completely removes ammonium, phosphorus, 17β-estradiol from diluted digestate, and removes 62% of zinc, 84% of manganese, 74% of cadmium and 99% of copper. 

/pdf/cultivation-of-microalgae-on-liquid-anaerobic-digestate-for-20mds1nq.pdf

Naveen kumar Rajendran

Papers

Investigation of CaO nanocatalyst synthesized from Acalypha indica leaves and its application in biodiesel production using waste cooking oil

Techno-economic analysis of food waste valorization for integrated production of polyhydroxyalkanoates and biofuels.

Process optimization, economic and environmental analysis of biodiesel production from food waste using a citrus fruit peel biochar catalyst

Process evaluation and techno-economic analysis of biodiesel production from marine macroalgae Codium tomentosum.

Techno-economic analysis and life cycle assessment of poly (butylene succinate) production using food waste.