Core–Shell Nanophotocatalysts: Review of Materials and Applications

Hybrid nanostructures and nanoarchitectures possess unique physicochemical properties such as high activity/functionality, enhanced physicochemical stability, and improved biocompatibility, which renders them suitable for various biomedical, pharmaceutical, environmental, and catalytic applications. In this context, core–shell nanophotocatalysts have shown superior activity compared to their counterparts, namely, their individual pristine semiconductors and composite materials components. Thus, the development of various innovative core–shell nanostructures as photocatalysts is of practical relevance in view of their unique properties with salient advantageous features applicable to, among others, the degradation of organic pollutants, energy storage, and H2 generation. Assorted techniques are deployed to synthesize core–shell nanostructures, including chemical vapor deposition, sol–gel, hydrothermal, spin-coating deposition, solvothermal, combustion waves, microwave (MW)- and ultrasonic-assisted, electrodeposition, laser ablation, and biological approaches. Because core–shell nanostructures provide an immense opportunity to have the most efficient photocatalysts with high stability and reproducibility; herein, the recent advances in this domain are discussed, comprising the most important fabrication techniques and diverse appliances including important challenges and unrealized opportunities.