The efficient and selective catalytic reduction of CO2 is a highly promising process for both of the storage of renewable energy as well as the production of valuable chemical feedstocks. In this work, we show that the addition of an ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate, in an aprotic electrolyte containing a proton source and FeTPP, promotes the in situ formation of the [Fe(0) TPP](2-) homogeneous catalyst at a less negative potential, resulting in lower overpotentials for the CO2 reduction (670 mV) and increased kinetics of electron transfer. This co-catalysis exhibits high Faradaic efficiency for CO production (93 %) and turnover number (2 740 000 after 4 hour electrolysis), with a four-fold increase in turnover frequency (TOF) when compared with the standard system without the ionic liquid.

Silicon-based impurities are ubiquitous in natural graphite. However, their role as a contaminant in exfoliated graphene and their influence on devices have been overlooked. Herein atomic resolution microscopy is used to highlight the existence of silicon-based contamination on various solution-processed graphene. We found these impurities are extremely persistent and thus utilising high purity graphite as a precursor is the only route to produce silicon-free graphene. These impurities are found to hamper the effective utilisation of graphene in whereby surface area is of paramount importance. When non-contaminated graphene is used to fabricate supercapacitor microelectrodes, a capacitance value closest to the predicted theoretical capacitance for graphene is obtained. We also demonstrate a versatile humidity sensor made from pure graphene oxide which achieves the highest sensitivity and the lowest limit of detection ever reported. Our findings constitute a vital milestone to achieve commercially viable and high performance graphene-based devices.

Managing carbon dioxide (CO2) released from large‐scale industrial processes is of great importance, yet there remain significant technical challenges. Herein, the fabrication of 1‐mm‐thick solid‐state electrochemical devices based on poly(ionic liquid) ionogels with embedded electrodes capable of both adsorption and electrochemical reduction of CO2 is reported. The ionogels are prepared via radical polymerization and chemical crosslinking of a vinyl imidazolium trifluoromethanesulfonimide ionic liquid monomer in the presence of additional ionic liquids (ILs) that act as swelling agents and enhance ionic conductivity. The effects of the ILs concentration and the degree of crosslinking on the mechanical properties, conductivity, and CO2 adsorption of the ionogels are investigated. The ionogels are shown to have ionic conductivities as high as 0.6 mS cm−1. The results of quartz crystal microbalance analyses demonstrates that the CO2 adsorption of the ionogels reaches up to ≈22 mg g−1, which is 10‐fold higher than that of their native ionic liquid. Moreover, the ionogels are easily recoverable after CO2 adsorption. The flexibility, conductivity, and CO2 capture capacity of this system can be controlled by the crosslinking ratio and ionic liquid content of the ionogels. This electrochemical device has the potential to be used in large scale plants for capturing CO2 for further electrochemical reactions.