Solar-driven CO 2 reduction by abundant water to alcohols can supply sustainable liquid fuels and alleviate global warming. However, the sluggish water oxidation reaction has been hardly reported to be efficient and selective in CO 2 conversion due to fast charge recombination. Here, using transient absorption spectroscopy, we demonstrate that microwave-synthesised carbon-dots (m CD) possess unique hole-accepting nature, prolonging the electron lifetime (t 50%) of carbon nitride (CN) by six folds, favouring a six-electron product. m CD-decorated CN stably produces stoichiometric oxygen and methanol from water and CO 2 with nearly 100% selectivity to methanol and internal quantum efficiency of 2.1% in the visible region, further confirmed by isotopic labelling. Such m CD rapidly extracts holes from CN and prevents the surface adsorption of methanol, favourably oxidising water over methanol and enhancing the selective CO 2 reduction to alcohols. This work provides a unique strategy for efficient and highly selective CO 2 reduction by water to high-value chemicals.

Controlled shifting of the CO2 reduction product from C1 to C2 hydrocarbons obtained with graphene wrapped blue titania under solar light.

Efficient removal of CO2 from enclosed environments is a significant challenge, particularly in human space flight where strict restrictions on mass and volume are present. To address this issue, this study describes the use of a multimaterial, layer-by-layer, additive manufacturing technique to directly print a structured multifunctional composite for CO2 sorption with embedded, intrinsic, heating capability to facilitate thermal desorption, removing the need for an external heat source from the system. This multifunctional composite is coprinted from an ink formulation based on zeolite 13X, and an electrically conductive sorbent ink formulation, which includes metal particles blended with the zeolite. The composites are characterized using analytical and imaging tools and then tested for CO2 adsorption/desorption. The resistivity of the conductive sorbent is <2 mΩ m, providing a temperature increase up to 200 °C under 7 V applied bias, which is sufficient to trigger CO2 desorption. The CO2 adsorption capability of the conductive zeolite ink appears to be unaffected by the presence of the conductive particles, meaning a large fraction of the total mass of the structured composite device is functional.

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