Synergistic Mechanism of 0D Internal and Surface Defects Regulation Coupled with Pyroelectric Effects for Optimizing the Photoelectrocatalytic Properties of CdS

Abstract Rational defect regulation is an effective way to enhance the performance of photoelectrocatalytic (PEC) water splitting. In this paper, we firstly constructed internal and surface defects to modulate the crystal structure of CdS, and investigated the synergistic impact of 0D (0‐dimensional) internal and surface defects regulation coupled with pyroelectric effects for optimizing the photoelectrocatalytic properties of CdS. It was found that the synergistic impact had a significant enhancement effect on the carrier separation and transfer, and the current density reached 3.93 mA/cm 2 at 1.23 V vs. RHE increased by 16.38 times, meanwhile, the stability of the photoelectrodes was greatly promoted. The advantages and intrinsic relationships are also described: the formation of 0D dual‐type of defects alters the atomic arrangement in the crystal, optimizes the energy band structure, reduces carrier recombination, and increases carrier density. What's more, the introduction of defects induces electron redistribution and changes the state of dipoles inside the crystal, thus increasing built‐in electric field and generating more thermally generated carriers to optimize the pyroelectric effect. This work demonstrates the feasibility of defect modulation for optimizing pyroelectric performance and photocatalytic performance and bringing new light to PEC water splitting.