(654e) CO2 Upgrading into Solid Carbon-Based Nanomaterials: From Reduced Graphene Oxide to Novel Materials

It has long been understood that carbon capture, utilization, and storage/sequestration (CCUS) strategies have not typically been economically incentivized until recently with the introduction of carbon-tax schemes. Capitalizing on initiative, such as the Paris Agreement, towards achieving net-zero greenhouse gas (GHG) emissions by 2050 seem far-fetched without active market intervention and greener regulated policies. To that end, emerging CO₂ capture and conversion technologies into value-added products have seen continued advances through electrochemical and thermochemical routes. Herein, we discuss a targeted approach towards upgrading CO₂ with synergistic high tunability and scalability. Further, we demonstrate how minor refinement to the feed stream can result in the development of novel materials with CO₂ as feed.

First, we adapt a thermochemical reduction technique that directly reduces CO₂ atop a catalytic Cu-based substrate into tunable quality reduced graphene oxide (rGO) through control of reaction humidity conditions, on-stream time, and morphology of catalytic substrate. Such operating parameters were found to have detrimental effects on rGO material properties including domain size, defect density, and degree of reduction (C/O ratio) to name a few. Second, we also give insight into different carbon nanomaterials (i.e., carbon nanotubes (CNTs)) that can be synthesized through rational modifications of this approach. Furthermore, we investigate a novel Cu-C-O material that was repeatably fabricated through direct reduction of CO₂ with H₂O as a mild reducing agent. Work on identifying the novel Cu-C-O complex structures is still ongoing due to the intrinsic novel structure of the attained materials. Nevertheless, an array of characterization techniques including, but not limited to, FESEM, HRTEM, EDS, XPS, XRD, AFM, solid-state C-NMR, amongst others have been conducted on this novel material. Certain features point towards it being the first ever reported Cu-based MXene-like structure. Various characterization techniques towards identifying and elucidating the properties of this novel material will be discussed.