Impacts of boron doping on the atomic structure, stability, and photocatalytic activity of Cu3P nanocrystals

Boron (B) has been engaged as a light and versatile dopant that can modify the crystal structure and intrinsic properties of host materials, enabling tunable electrocatalytic properties. However, the role of B dopant in photocatalytic reactions is still elusive. Herein, we report the preparation of B-doped Cu3P nanocrystals (B-Cu3P) that shows an almost four-time promotion of photocatalytic hydrogen production rate compared with pristine Cu3P. This improvement is credited to the replacement of P with B atoms, which modifies atomic configuration and bonding environments of Cu3P and endows with enhanced photostability and charge carrier generation. Computational calculations indicate that the boron-associated reconfiguration of electronic structure improves the conductivity of B-Cu3P by downshifting the Fermi level, leading to a higher charge density and optimized Gibbs free energy of H adsorption. This work demonstrates the role of B-doping in revamping transition metal phosphides with improved kinetics and thermodynamics for photocatalytic reactions.