Few-Layer Black Phosphorus Nanosheets: A Metal-Free Cocatalyst for Photocatalytic Nitrogen Fixation.

Exploiting an appropriate strategy to prepare fine crystal quality black phosphorus nanosheets (BPNSs) catalyst is a major challenge for its practical application in catalysis. Herein, we address this challenge by developing a rapid electrochemical expansion strategy for scale preparation of fine crystal quality BPNSs from bulk black phosphorus, which was demonstrated to be an active cocatalyst for photocatalytic nitrogen fixation in the presence of CdS as a photocatalyst. The transient photocurrent and charge density studies show that the BPNSs can efficiently accelerate charge separation of CdS, leading to the enhanced photocatalytic activities of BPNSs/CdS nanocomposites for nitrogen fixation. The 1.5% BPNSs/CdS photocatalyst exhibits the highest photocatalytic activity for nitrogen fixation with a NH3 evolution rate of 61.63 μmol•L-1•h-1. This study not only affords a rapid and simple strategy for scale synthesis of fine crystal quality BPNSs but also provides new insight into the design and development of black phosphorus-based materials as low-cost metal-free cocatalyst for photocatalytic nitrogen fixation.