Recently, defect architectured photocatalysis is proved to be the most versatile choice for high solar to chemical energy conversion processes. Defect engineering strategies are of great demand to effectively tune the electronic microstructure and surface morphologies of semiconductors to boost charge carrier concentration and extend light harvesting capability. This review provides a comprehensive insight to various kinds of defects along with their synthesis procedures and controlling mechanism to uplift photocatalytic activity. In addition, the contribution made by defects and material optimization techniques toward electronic band structure of the photocatalyst, the optimal concentration of defects, the key adsorption processes, charge distribution, and transfer dynamics have been explained in detail. Further, to clarify the relationship between photocatalytic activity and defect states in real, a comprehensive outlook to the versatile photocatalytic applications has been presented to highlight current challenges and future applications. Defect engineering therefore stands as the next step toward advancement in the design and configuration of modern photocatalysts for high efficiency photocatalysis.

Rational design hybrid nanostructure photocatalysts with efficient charge separation and transfer, and good solar light harvesting ability have critical significance for achieving high solar‐to‐chemical conversion efficiency. Here a highly active and stable composite photocatalyst is reported by integrating ultrathin ZnIn₂S₄ nanosheets on surface of hollow CdS cube to form the cube‐in‐cube structure. Experimental results combined with density functional theory calculations confirm that the Z‐scheme ZnIn₂S₄/CdS heterojunction is formed, which highly boosts the charge separation and transfer under the local‐electric‐field at semiconductor/semiconductor interface, and thus prolongs their lifetimes. Moreover, such a structure affords the highly enhanced light‐harvesting property. The optimized ZnIn₂S₄/CdS nanohybrids exhibit superior H₂ generation rate under visible‐light irradiation (λ ≥ 420 nm) with excellent photochemical stability during 20 h continuous operation.

Cocatalysts-free SrTiO₃ nanofibers with high photocatalytic performance are developed by incorporating oxygen vacancies (OVs), where OVs could steer charge behaviors, serve as active sites and heighten reduction ability of electrons.

The functions of metal–phenolic networks (MPNs) and polyphenol derivatives in photo(electro)catalysis reactions are summarized, encompassing improving interfacial charge carrier separation, accelerating surface reaction kinetics, and enhancing light absorption.