The active role of nanocarbons in electrocatalysis: recent advances in CO2 conversion

The electrocatalytic reduction of CO2 (CO2RR) powered by renewable energy offers a promising strategy to mitigate climate change while generating valuable fuels and chemicals. Achieving high performance in this process strongly depends on the properties of the electrode materials and the overall electrode architecture. In this context, nanocarbon materials, generally used as supports, are far from being inert; they can actively influence CO2RR by stabilising adsorbed intermediates and directing reaction pathways through their hydrophobicity, porosity and defective structure. Unlike most reviews that focus exclusively on the active metal phase, this mini-review highlights the emerging dual role of nanocarbons (acting both as substrates and as active components) in determining catalytic activity and selectivity. It summarises recent advances in CO2RR using nanocarbon-based materials, including both metal-free and hybrid systems, and discusses how doping and interfacial engineering enhance CO2 activation, product selectivity and process efficiency. Gas-diffusion electrodes incorporating nanocarbon architectures improve mass transport and triple-phase boundary formation (gas-solid-liquid interface), enabling high current densities and multi-carbon product generation. These aspects demonstrate that tuning nanocarbon properties is essential for developing efficient and scalable CO2RR electrodes, thereby advancing sustainable carbon utilisation technologies.