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Nanocomposites emerged as suitable alternatives for electrode materials, are defined as “two or more materials with different properties remain separate and distinct on a macroscopic level within one unity and with any dimension in any phase less than 100 nm”. Recently, polymer/carbon based nanocomposites have attracted significant research interests for energy applications due to their multi-functionalities, improved structure stability and ease of production. This dissertation work focusing on the development of innovative electrode nanocomposites for proton exchange membrane fuel cell, supercapacitor and electrochromic applications. Chapter 1 is an introduction. Chapter 2 & 3 focus on the synthesis of Pd-based nanocatalysts for EOR [ethanol oxidation reaction]. The effect of Pd loading in Pd/MWNTs [multi-walled carbon nanotubes], the conversion of Pd precursor and the variation of functionalized carboxylic groups on tube wall surface have been investigated through varying precursor ratios. A follow-up work focusing on integrating E [oxyphilic metal] and MO [metal oxides] into Pd/MWNTs nanocatalysts proceeds in Chapter 3. Ultrafine FePd nanoalloys deposited on γ-Fe2O3 [gamma iron oxides], FePd-Fe2O3, anchored on MWNTs, FePd-Fe2O3/MWNTs, have been successfully synthesized for EOR. A 3.65 fold increase of peak current density compared with that of Pd/MWNTs was observed in cyclic voltammetry after normalizing to Pd mass. Chapter 4 & 5 focus on the synthesis of electrode nanocomposites for supercapacitor and electrochromic applications, hybrid PANI [polyaniline] and MnFe2O4 [manganese iron oxide] nanocomposites film has been successfully synthesized for combined electrochromic and energy storage applications. The synthesized hybrid film exhibited enhanced electrochromic and energy storage performances compared to pristine PANI film due to the synergistic effect between the nanofillers and PANI matrix, nanofiller resulted porous structure of PANI and energy storage contribution of MnFe2O4. Chapter 5 presents a facile hydrothermal method to enhance the energy storage property of graphene by employing KOH activation and N-doping processes. The synthesized graphene exhibited largely enhanced capacitance (186.63 F/g) and cycling stability compared with that of N-G [nitrogen doped graphene, 50.88 F/g] and AG [activated graphene, 58.38 F/g] due to the increased defects on graphene sheet and the introduced active N defects. Conclusions and future work are provided in Chapter 6.

The use of dyes has become very significant across various industries such as textiles, paper, and clothing. The organic chemical composition of dyes is a major concern when discharging wastewater not only into the environment, but also within wastewater treatment plants. Dye effluent consists of high chemical oxygen demand (COD) and also color, components that require treatment before discharge. As a result, federal legislation has required industries that discharge high components in wastewater to undergo treatment within the plants. Within literature, authors have considered various biological, physical, and chemical methods of treating dye wastewater. Recently, electrocoagulation/electroflotation (ECF) has been an additional method of treatment that has been considered for the treatment of dye wastewater. Two separate studies are considered. First, Acid Yellow 11 (AY11) at a concentration of 25 mg/L (by weight) underwent treatment from three different coagulants (Alum, Ferric Sulfate, and Ferric Chloride) , under three different strengths (5 mg/L, 10 mg/L, and 15 mg/L), and two different initial pH considerations (4 and 7) for the purpose of analyzing color removal. Following the study, the results were collaborating into a response surface methodology, developing an equation for the three different coagulants. In addition, a Box-Behnken design has been setup for the purpose of considering the effects of pH, dye concentration, dye type, coagulant type and strength on the efficiency of electrocoagulation. These values will be analyzed using statistical analysis, along with toxicity study done on the effectiveness of removing toxic contaminants from the wastewater. Finally, a photo-oxidation study was completed on Acid Orange 7 (AO7) synthetic dye wastewater for the purpose of determining the effects of photo-oxidation based on dye concentration, catalyst type and dose. Langmuir-Hinshelwood coefficients were developed based on the results of this experiment.