Graphene oxide (GO) decorated with silver (Ag), copper (Cu) or platinum (Pt) nanoparticles that are anchored on dodecylbenzene sulfonic acid (DBSA)-doped polyaniline (PANI) were prepared by a simple one-step method and applied as novel materials for high performance supercapacitors. High-resolution transmission electron microscopy (HRTEM) and high-resolution scanning electron microscopy (HRSEM) analyses revealed that a metal-decorated polymer matrix is embedded within the GO sheet. This caused the M/DBSA–PANI (M = Ag, Cu or Pt) particles to adsorb on the surface of the GO sheets, appearing as aggregated dark regions in the HRSEM images. The Fourier transform infrared (FTIR) spectroscopy studies revealed that GO was successfully produced and decorated with Ag, Cu or Pt nanoparticles anchored on DBSA–PANI. This was confirmed by the appearance of the GO signature epoxy C–O vibration band at 1040 cm−1 (which decreased upon the introduction of metal nanoparticle) and the PANI characteristic N–H stretching vibration band at 3144 cm−1 present only in the GO/M/DBSA–PANI systems. The composites were tested for their suitability as supercapacitor materials; and specific capacitance values of 206.4, 192.8 and 227.2 F·g−1 were determined for GO/Ag/DBSA–PANI, GO/Cu/DBSA–PANI and GO/Pt/DBSA–PANI, respectively. The GO/Pt/DBSA–PANI electrode exhibited the best specific capacitance value of the three electrodes and also had twice the specific capacitance value reported for Graphene/MnO2//ACN (113.5 F·g−1). This makes GO/Pt/DBSA–PANI a very promising organic supercapacitor material.

Lithium manganese phosphate nanoparticles (LiMnPO 4 ; LMP) as well as the nickel-doped (LMNP) and graphenised derivatives (G-LMNP) were synthesized. Electrochemical characteristics of the materials were examined using cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge-discharge. Lithium ion capacitors (LIC) fabricated using LMP and composite materials as positive electrodes and activated carbon as the negative electrode, exhibited a specific capacitance of 60 F g À 1 at a current load of 0.1 A g À 1 for the AC//G-LMNP LIC. Capacitance retention of 83 % was obtained by the AC//G-LMNP LIC after 750 cycles, with a high specific power of 19 kW kg À 1 at 0.5 A g À 1 .

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Symmmetrically oriented Pd (100) and its bimetallic Pd (100)Ru electrocatalysts were chemically synthesized and their conductive properties employed in the electrochemical oxidation of ammonia. Electrochemical data based on EIS, SWV and CV revealed that the Pt/Pd (100)Ru electrode showed a better conductivity and higher catalytic response towards the electrooxidation of ammonia compared to Pt/Pd (100) electrode. This was demonstrated by the EIS results where Pt/Pd (100)Ru gave a charge transfer resistance (Rct) of 48.64 Ω, high exchange current and lower time constant (5.2738 x 10-1A and 3.2802 x 10-7 s /rad) values while the Pt/Pd (100) had values of 173.2 Ω, 1.4811 x 10-1A and 4.8321 10-7 s /rad. The drastic drop in Rct highlights the superiority of the Pt/Pd (100)Ru over the Pt/Pd (100) and confirms that facile interfacial electron transfer processes occur on the Pt/Pd (100)Ru electrode during the electrocatalytic ammonia oxidation. Investigations through voltammetry revealed that the Pt/Pd (100)Ru had a higher peak current density and a shift in potential to more negative values at ≈ -0.2 V and ≈ -0.4 V. The EASA value of Pt/Pd (100)Ru was found to be 119.24 cm2 whereas Pt/Pd (100) had value of 75.07 cm2. The high electrochemically active surface area of Pd (100)Ru at 119.24 cm2 compared to the 75.07 cm2 for Pd (100) strengthened this observation in performance between the two catalysts for ammonia electrooxidation.