Enabling Efficient Photocatalytic Hydrogen Evolution via In Situ Loading of Ni Single Atomic Sites on Red Phosphorus Quantum Dots

Currently, red phosphorus (RP) based catalysts have shown great potential for photocatalysis due to several important intrinsic advantages. The integration of single atomic sites and RP becomes a promising solution, which has rarely been discussed. Herein, a brand-new type of photocatalyst is proposed by in situ loading Ni single atoms on the P vacancy defects of the RP quantum dots (Ni-RPQD), achieving the successful attempt of combining single atomic catalyst (SAC), RP, and QDs for the first time. The Ni-P sites act as electron antennas, which attract the photocarriers to the solid-liquid interface and activate protons to initiate an efficient hydrogen production process, resulting in a high hydrogen production rate, which is 224 times higher than that of the original RPQD and is also superior to most reported RP-based photocatalysts and competitive with the non-noble metal-based SAC photocatalysts. Theoretical explorations reveal that the atomically dispersed Ni atoms significantly lower the energy barrier for electron transfer during photocatalysis. This results in enhanced adsorption and fast dissociation of water molecules for more efficient H₂ generation. This study offers a significant and new direction for future developments of advanced and stable photocatalysts for water splitting.