Directional Charge Pumping from Photoactive P‐doped CdS to Catalytic Active Ni2P via Funneled Bandgap and Bridged Interface for Greatly Enhanced Photocatalytic H2 Evolution

Abstract Loading cocatalysts onto semiconductors is one of the most popular strategies to inhibit charge recombination, but the efficiency is generally hindered by the localized built‐in electric field and the weakly connected interface. Here, this work designs and synthesizes a 1D P‐doped CdS nanowire/Ni 2 P heterojunction with gradient doped P to address the challenges. In the composite, the gradient P doping not only creates a funneled bandgap structure with a built‐in electric field oriented from the bulk of P‐CdS to the surface, but also facilitates the formation of a tightly connected interface using the co‐shared P element. Consequently, the photogenerated charge carriers are enabled to be pumped from inside to surface of the P‐CdS and then smoothly across the interface to the Ni 2 P. The as‐obtained P‐CdS/Ni 2 P displays high visible‐light‐driven H 2 evolution rate of ≈8265 µmol g −1 h −1 , which is 336 times and 120 times as that of CdS and P‐CdS, respectively. This work is anticipated to inspire more research attention for designing new gradient‐doped semiconductor/cocatalyst heterojunction photocatalysts with bridged interface for efficient solar energy conversion.