Hybrid Semiconductor–Metal Nanorods as Photocatalysts

Semiconductor–metal hybrid nanoparticles manifest combined and often synergistic properties exceeding the functionality of the individual components, thereby opening up interesting opportunities for controlling their properties through the direct manipulation of their unique semiconductor–metal interface. Upon light absorption, these structures exhibit spatial charge separation across the semiconductor–metal junction. A significant and challenging application involves the use of these nanoparticles as photocatalysts. Through this process, the charge carriers transferred to the metal co-catalyst are available as reduction or oxidation reagents to drive the surface chemical reactions. In this review, we discuss synthesis approaches that offer a high degree of control over the hybrid nanoparticle structure and composition, the number of catalytic sites and the interfacial characteristics, including examples of a variety of photocatalyst architectures. We describe the structural and surface effects with regard to the functionality of hybrid nanosystems in photocatalysis, along with the effects of solution and chemical conditions on photocatalytic activity and efficiency. We conclude with a perspective on the rational design of advanced semiconductor–metal hybrid nanoparticles towards their functionality as highly efficient photocatalysts.