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.

Controlling product branching ratios in a chemical reaction represents a desired but difficult achievement in chemistry. In this work, we demonstrate the first example of altering the branching ratios in a multichannel reaction, i.e., methanol dissociative chemisorption on Cu(111), via selectively exciting specific vibrational modes. To this end, we develop a globally accurate full-dimensional potential energy surface for the CH3OH/Cu(111) system and perform extensive vibrational state-selected molecular dynamics simulations. Our results show that O–H/C–H/C–O stretching vibrational excitations substantially enhance the respective bond scission processes, representing extraordinary bond selectivity. At a given total energy, the branching ratio of C–O/C–H dissociation can increase by as large as 100 times by exciting the C–O stretching mode which possesses an unprecedentedly strong vibrational efficacy on reactivity. This vibrational control can be realized by the well-designed experiment using a linearly polarized laser.

Eley-Rideal (ER) reaction between a projectile and an adsorbate at a gas-surface interface represents many interesting dynamic features. Electron-hole pairs (EHPs) could play an important role in this process, given the interaction between the accelerated incident atom/molecule and the surface electrons. Here, we examine the EHP effects in a benchmark ER reaction of an impinging H/D atom and pre-covered D/H atoms on Cu(111) by ab initio molecular dynamics simulations. It is found that energy dissipation to EHPs lowers the reaction cross sections by ∼1/3, mainly due to the suppression of the hot atom mechanism, but has a minor effect on rotational distributions, leading to quantitative agreement with experimental data. More interestingly, electronic excitation is responsible for the isotopic effect in translational energy distributions, but probably not for that in angular distributions. Our results highlight the specific role of electronic excitation in detailed dynamic quantities in the ER process.