Homogeneous dual-site P lattice doping in CdS quantum rods for visible-light photocatalytic water splitting

Dual-site lattice doping in semiconductor materials is highly promising for photocatalysis as it can tune the sub-band electronic structure and charge distribution of the photocatalyst. However, it is challenging to precisely regulate the band structure by dual-site doping using the same heteroatom. Herein, we report the homogeneous dual-site P lattice doping in CdS quantum rods, i.e. P is homogeneously doped into both substitutional site of S and interstitial site, leading to negative shift of valence and conduction bands with extraordinary visible-light excitation efficiency. The electrons generated in the newly designed photocatalyst have strong redox potential in reducing H⁺ into H₂ in photocatalysis. By introducing nontrivial co-catalyst Ni₃C quantum dots onto the surface of P-CdS quantum rods, the apparent quantum efficiency of the catalyst achieves 15.7% at 435 nm, which is 5 times higher than that of pristine CdS.