Atomically Dispersed Co-P3 on CdS Nanorods with Electron-Rich Feature Boosts Photocatalysis

Abstract

The development of highly efficient photocatalytic systems with rapid photogenerated charge separation and high surface catalytic activity is highly desirable for the storage and conversion of solar energy, yet remains a grand challenge. Herein, a conceptionally new form of atomically dispersed Co-P₃ species on CdS nanorods (CoPSA-CdS) is designed and synthesized for achieving unprecedented photocatalytic activity for the dehydrogenation of formic acid (FA) to hydrogen. X-ray absorption near edge structure, X-ray photoelectron spectroscopy, and time-resolved photoluminescence results confirm that the Co-P₃ species have a unique electron-rich feature, greatly improving the efficiency of photogenerated charge separation through an interface charge effect. The in situ attenuated total reflection infrared spectra reveal that the Co-P₃ species can achieve much better dissociation adsorption of FA and activation of CH bonds than traditional sulfur-coordinated Co single atom-loaded CdS nanorods (CoSSA-CdS). These two new features make CoPSA-CdS exhibit the unprecedented 50-fold higher activity in the photocatalytic dehydrogenation of FA than CoSSA-CdS, and also much better activity than the Ru-, Rh-, Pd-, or Pt-loaded CdS. Besides, CoPSA-CdS also shows the highest mass activity (34309 mmol g_Co ^-1 h^-1 ) of Co reported to date. First-principles simulation reveals that the Co-P₃ species herein can form an active PHCOO intermediate for enhancing the rate-determining dissociation adsorption of FA.

Keywords: Co single atoms; formic acid dehydrogenation; non-noble metal catalysts; phosphorus coordination; photocatalysis.