Sundar Mayavan

Graphene ink as a corrosion inhibiting blanket for iron in an aggressive chloride environment

Corrosion resistance of iron (Fe) was achieved by coating it with a reduced graphene oxide ink. The Fe surface with the graphene oxide ink coating exhibited improved corrosion resistance in an aggressive chloride environment, which is attributed to the excellent barrier property of graphene. The advantage of this method is that graphene can be deposited by using a solution process that is easy, reproducible, and can be used to coat objects of any dimensions just like conventional paints or coatings.

Effect of graphene and carbon nanotubes on the negative active materials of lead acid batteries operating under high-rate partial-state-of-charge operation

The consequences of including graphene and carbon nanotubes in the negative plates of lead acid batteries have been investigated after exposure to a high rate partial state of charge duty cycle.

Mesoporous silica based reservoir for the active protection of mild steel in an aggressive chloride ion environment

Spherical mesoporous silica (m-SiO2) with well-ordered pores was synthesized by a modified Stober method using CTAB micelles. The as-prepared silica was used as a reservoir to load a corrosion inhibitor. Steel samples that were coated with the inhibitor loaded silica reservoir exhibited improved corrosion resistance compared to the samples without the silica reservoir in an aggressive chloride environment. Localised electrochemical impedance spectroscopy (LEIS) and scanning vibrating electrode technique (SVET) data suggest that inhibitor release is triggered by the local corrosion phenomena, which leads to active protection of the metal.

One-step synthesis of boron nitride carbon nanosheets containing zinc oxide for catalysis of the oxygen reduction reaction and degradation of organic dyes

Boron nitride carbon nanosheets containing zinc oxide (ZnO/h-BNC) with a hexagonal B–N bond structure were prepared using a scalable, one-step process involving the thermal treatment of glycine, zinc nitrate, graphene oxide and boron oxide. The as-prepared ZnO/h-BNC hybrids were active for both the electrocatalytic reduction of oxygen under alkaline conditions and the photocatalytic oxidation of methyl orange dye. The ZnO/h-BNC nanosheets showed a much improved onset potential and reduced current density compared with ZnO/BCN sheets with a dominant CN bond configuration for the oxygen reduction reaction (ORR). The BNC enriched with h-BN showed an excellent ORR performance, whereas the CN dominant BCN showed relatively less activity for the ORR, suggesting an intrinsic difference in properties of the BCN-based materials with different bond configurations. The Zn species located inside the h-BNC matrix acted as photocatalytically active centres for the degradation of methyl orange dye under UV irradiation.

BCN–Co3O4 hybrid – a highly efficient catalyst for the oxygen evolution reaction and dye degradation

A simple one-step procedure for the preparation of nanosheets of crystalline 2D boron carbon nitride containing cobalt oxide (Co3O4–BCN) involving glycine–nitrate combustion chemistry is reported. The as-prepared hybrid is a highly active catalyst for dye degradation, and for the water oxidation reaction as compared to pristine Co3O4. Co3O4–BCN shows enhanced catalytic activity for the oxygen evolution reaction (OER) in alkaline electrolyte. The onset potential towards the OER is 0.406 V (vs. Ag/AgCl) in 1 M KOH. A current density of 10 mA cm−2 has been achieved at an overpotential of 394 mV in 1 M KOH. The as-prepared hybrid exhibits highly-efficient degradation ability for methyl orange and methyl blue dyes under direct sunlight irradiation.

Evaluating the performance of MoS2 based materials for corrosion protection of mild steel in an aggressive chloride environment

In this work for the first time, metal doped (Fe, Co, Ni) MoS2 sheets dispersed in sunflower oil were explored as a coating for inhibiting Fe metal corrosion in a sodium chloride (NaCl) solution. The incorporation of Fe, Co, and Ni ions resulted in an appreciable increase in the corrosion resistance properties of MoS2.

Effect of boron–carbon–nitride as a negative additive for lead acid batteries operating under high-rate partial-state-of-charge conditions

The consequences of including boron carbon nitride (BCN) in the negative plates of lead acid batteries have been investigated after exposure to high rate partial state of charge duty cycles. For BCN-NAM, the dominating elementary process is the formation of PbO instead of PbSO4. The BCN disintegrates to form carbon and nitrogen species on cycling that improve the performance of BCN-NAM under HRPSoC cycling.

Effect of using sonicated sulphuric acid as an electrolyte in a lead acid battery

The consequences of adding sonicated sulphuric acid as an electrolyte in a lead acid battery (LAB) have been investigated. The LAB fabricated using sonicated sulphuric acid electrolyte shows improved performance (electrolyte conductivity and capacity) than LAB with normal sulphuric acid electrolyte.