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Interest in graphitizing hard carbons has peeked in recent years due to the applications of graphitic carbon in energy storage applications and the need to transition to greener energy and transportation. Hard carbons have initially been graphitized with the use of metal catalysts but a downside to this method is the occurrence of metal impurities in the resultant graphitic carbon which then makes it detrimental to applications. Moreover, the process of purification could also be costly. This dissertation aims to present a novel technique—templating using 2-dimensional (2D) nanomaterials—to graphitize model hard carbons. The scope of this dissertation answers the following: ❖ Does carbonization pressure affect the graphitization of soft and hard carbons? ❖ Are the characteristics/properties of 2D nanomaterials effective in templating and aiding graphitization of model hard carbons? ❖ What mechanisms are operative during templating graphitization and what are their contributions? ❖ How do the properties of the modified hard carbons influence their performance in energy storage applications? To address the aforementioned questions, in-depth studies, and novel processes were employed. The first part of this thesis explores the role of carbonization pressure in the graphitization of model soft and hard carbons. The model soft and hard carbons were subjected to carbonization under autogenic and atmospheric pressure conditions and their graphitic evolution at different high temperatures treatments was characterized. Next, the thesis explores the effect of 2D nanomaterials in the form of graphene oxide and its derivatives in inducing the graphitization of phenolic resin, novolac. Two mechanisms were identified (physical and chemical templating) as operative in aiding the graphitization of the novolac matrix. The thesis further explores the templating technique on the graphitization of a biomaterial, lignin, where methods were employed to improve the interactions between the lignin matrix and the graphene oxide additives. The results from the above-described work in the phenolic resin and biomaterial prompted the need for an in-depth understanding of the templating mechanisms and their contributing factor to graphitization. In this regard, the thesis then scrutinizes the predominant force and operative mechanism driving graphitization— physical templating versus chemical templating. Finally, the thesis assesses the influence of the properties of modified hard carbons in energy storage applications and provides strategies for performance improvement. Collectively, the important contribution of this thesis is centered on the development of 2D nanomaterial templating in inducing graphitization of hard carbons (which requires no purification process for the resultant graphitic carbon), understanding the templating mechanisms interplay in modifying and tailoring crystalline properties in hard carbons and lastly, highlighting the electrochemical performance of the modified hard carbons in energy storage applications. 

ur previous work investigated the templating ability of graphene oxide-derived additives to induce graphitization of the novolac matrix. The findings led to two working hypotheses: the additives act as templates that promote matrix aromatic alignment to their basal planes during carbonization (referred to here as physical templating) in addition to forming radical edge sites that bond to the decomposing matrix (referred to here as chemical templating). However, results mainly underscored the role of functional groups on the GO additives (chemical templating). The aim of this current work seeks to differentiate the contributions of the operative mechanisms on graphitization. To study this, 2D materials with minimal oxygen functionalization, graphene and hexagonal boron nitride (hBN) were used as templates to induce graphitization of novolac matrix. First, the optimum weight percent of the 2D materials was determined with the composite graphitic quality measured by X-ray diffraction and Raman spectroscopy. Results revealed that hBN did not induce graphitization of novolac and was attributed to the absence of a sp² framework in hBN, unable to provide the crucial π-π interactions with the aromatic rings of the matrix. In contrast, the graphene additives mirrored one another and showed improved graphitization of the novolac. From these results, it was surmised that both mechanisms are operative; while physical templating offers control over long-range order in the form of crystallite height, chemical templating contributes to carbon reorganization and lateral growth extent. 

Techniques to improve the graphitization of lignin, the second most abundant natural polymer, are in great demand as a viable means to obtain cost- effective and less energy-intensive graphite for various applications. In this work, we report the effects of two-dimensional nanomaterials, graphene oxide (GO) and its derivative, reduced graphene oxide (RGO), used as templating agents for the graphitization of alkali-derived lignin. The hypothesis is that during heat temperature treatment, the GO additives act as a template that allows the lignin matrix to align on its basal planes through π−π interactions. In addition, possible chemical bonding between the GO additives and lignin may extend the two planar frameworks. Results from X-ray diffraction and Raman spectroscopy showed improved graphitic quality in the lignin-GO and lignin-RGO samples compared to pure lignin at 2500 °C. Transmission electron microscopy images and selected area electron diffraction patterns also revealed ordered nanostructures and defined polycrystalline patterns in the lignin-GO and lignin-RGO samples. This work presents a method to synthesize graphitic-like materials using carbon-based templates with the advantage that there is no need for further purification of the final material as in the case of transition metal catalysts. 

Increasing graphite demand for energy storage applications creates the need to make graphite using precursors and processes that are affordable and friendly to the environment. Non-graphitizing precursors such as biomass or polymers are known for their low cost and sustainability; therefore, graphitizing them will be an accom- plishment. In this work, a process of converting a non-graphitizing precursor, phenolic resin novolac (N), into a graphitic carbon is presented. This was achieved by the addition of five additives categorized as graphene oxide (GO) and its derivatives with varied oxygen concentrations. The hypothesis is that the additives act as templates that promote matrix aromatic alignment to their basal planes during carbonization (physical templating) in addition to forming radical sites that bond to the decomposing matrix (chemical templating). Results showed that the addition of reduced graphene oxide (RGO) additives of approximately 15.4 at.(%) oxygen content to the novolac matrix (RGO-N) show the best graphitic quality. In contrast, the addition of GO additive of twice or more oxygen content ≥30.8 at.(%) to the novolac matrix (GO-N) led to poor graphitic quality. This suggests that there is an optimum amount of oxygen content in GO additives needed to induce graphitization of the novolac matrix.