Plasmonic Metal Nanoparticles Decorated ZnO Nanostructures for Photoelectrochemical (PEC) Applications

Sunlight harvesting for energy generation and environmental remediation is an evolving research area which potentially opens a propitious avenue and beneficial to tackle energy and the environment issues. Conversion of sunlight into hydrogen or electricity through photoelectrochemical (PEC) cell is one of the most auspicious approaches for a feasible energy supply in which extensive development of photoelectrode is the key. Last few years witnessed the outstanding PEC performance flourished due to incorporating complexity in ZnO nanostructures and decorating them by metal nanoparticles. This chapter gives an overview of the current state of metal nanoparticles decorated ZnO nanostructures for PEC application. We discuss worthwhile role of ZnO and its key properties such as crystal structure, morphologies, and band potential beneficial from PEC viewpoint. A brief discussion on the basics of localized surface plasmon resonance (LSPR) shown by plasmonic metal nanoparticles followed by its capability towards increment in the PEC performance is displayed. Hybrids of metal nanoparticles decorated on ZnO have been utilized as photoelectrodes because of amazing features like enhanced visible light harvesting due to LSPR, higher conductivity, quicker charge transfer rate, increased photogenerated charge carrier separation, supporting band bending mechanism leading to long stability and high efficiency of PEC cell. All such features are explored in a systematic manner. A comparative section is dedicated to doped and decorated photoelectrodes for PEC studies. Rather being descriptive or thoroughgoing, this chapter talks about representative examples of novel and recent ideas to amplify PEC performance. Finally, conclusion point outs current challenges and gives an outlook.