Size-dependent activity and selectivity of carbon dioxide photocatalytic reduction over platinum nanoparticles

Abstract

Platinum nanoparticles (Pt NPs) are one of the most efficient cocatalysts in photocatalysis, and their size determines the activity and the selectivity of the catalytic reaction. Nevertheless, an in-depth understanding of the platinum’s size effect in the carbon dioxide photocatalytic reduction is still lacking. Through analyses of the geometric features and electronic properties with variable-sized Pt NPs, here we show a prominent size effect of Pt NPs in both the activity and selectivity of carbon dioxide photocatalytic reduction. Decreasing the size of Pt NPs promotes the charge transfer efficiency, and thus enhances both the carbon dioxide photocatalytic reduction and hydrogen evolution reaction (HER) activity, but leads to higher selectivity towards hydrogen over methane. Combining experimental results and theoretical calculations, in Pt NPs, the terrace sites are revealed as the active sites for methane generation; meanwhile, the low-coordinated sites are more favorable in the competing HER.

Highly Efficient Photoreduction of Low‐Concentration CO2to Syngas by Using a Polyoxometalates/RuIIComposite

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Macroscopic Spontaneous Polarization and Surface Oxygen Vacancies Collaboratively Boosting CO2 Photoreduction on BiOIO3 Single Crystals

“…Solar‐driven CO 2 reduction has attracted increasing attention for the mitigation of greenhouse effect and generation of renewable fuels – . However, the unsatisfied separation efficiency of photogenerated charge carries is one of the most critical issues that remarkably restricts the performance of semiconductor photocatalysts . During the photocatalytic process, the recombination of photogenerated electrons (e − ) and holes (h + ) in bulk phase (happening within several ps) is much faster than their migration from bulk to surface (happening within hundreds of ps); recombination of the charge carriers on the catalyst's surface (happening within dozens of ps) occurs more quickly than their participation in the catalytic reactions (ranging from several ns to several ms) .…”

A Mechanism Investigation of how the Alloying Effect Improves the Photocatalytic Nitrate Reduction Activity of Bismuth Oxyhalide Nanosheets

“…Generally, the photocatalytic properties of semiconductors are strongly related to their crystallinity and surface properties, such as morphology, specific surface area, as well as surface feature . Since the samples have similar morphological structures and specific surface areas, we explored their surface features.…”