Single Cobalt Atom Anchored Black Phosphorous Nanosheets as an Effective Cocatalyst Promotes Photocatalysis

Abstract Exploring novel cocatalysts with sufficient active sites and rapid photogenerated carrier separation remains challenge for boosting photocatalytic reactions. Recently, two‐dimensional (2D) black phosphorus (BP) has been developed and recognized to be an ideal platform for anchoring metal ions through lone pair electrons. Herein, we propose a new structure that cobalt atomically dispersed on BP nanosheets (BP−Co), and apply it as cocatalyst for photocatalytic H 2 evolution and CO 2 reduction under visible light (>420 nm) irradiation. Both scanning transmission electron microscope and X‐ray absorption near edge structure verified the existence of phosphorous‐coordinated Co sites. The interaction between Co and P brings greatly improvement on photocatalytic activities, and 18‐fold enhancement can be achieved on CdS when taking BP−Co as a noble‐metal‐free cocatalyst for H 2 evolution, which is higher than that of Pt under the same conditions. Besides, BP−Co can also be used as an effective cocatalyst to promote photocatalytic CO 2 reduction in the presence of photosensitizer [Ru(2, 2’‐bipyridy) 3 ]Cl 2 with a CO evolution rate of 88.6 μmol h −1 , superior to those obtained from the state‐of‐the‐art cocatalysts. It is anticipated that the current work might provide basic understanding as well as new opportunities on 2D BP nanosheets for versatile photocatalytic reactions.