Interfacial Bond Dipole Engineering for Accelerated Photogenerated Charge Migration in a Red Phosphorus Based...

Area of Science:

• Materials Science
• Photocatalysis
• Surface Chemistry

Background:

• Optimizing electron transfer kinetics at heterojunction interfaces is vital for efficient photocatalysis.
• Interfacial dipoles significantly influence charge carrier dynamics.

Purpose of the Study:

• To establish interfacial bond polarity as a universal descriptor for electron transfer kinetics.
• To investigate the role of interfacial dipole strength in heterojunction photocatalysts.

Main Methods:

• Density Functional Theory (DFT) calculations to determine interfacial dipole moments.
• Femtosecond transient absorption spectroscopy (fs-TAS) to measure electron transfer rates.
• Photocatalytic hydrogen evolution (PHE) experiments to assess catalyst performance.

Main Results:

• RP/CdS exhibited a stronger interfacial dipole (2.75 D) compared to RP/S8 (1.83 D).
• RP/CdS showed significantly faster interfacial electron transfer (5.5 × 10^9 s^-1) than RP/S8 (2.5 × 10^8 s^-1).
• RP/CdS demonstrated a 4.5-fold enhancement in PHE activity over its mechanical mixture, outperforming RP/S8.

Conclusions:

• Interfacial bond polarity is a key factor controlling electron transfer rates in heterojunctions.
• Engineering stronger interfacial dipoles is a promising strategy for designing high-performance heterojunction photocatalysts.
• This work provides a new perspective for rational design of advanced photocatalytic materials.