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Individual Highlight

Highly-Efficient Capillary Photoelectrochemical Water Splitting Using Cellulose Nanofiber-Templated TiO2 Photoanodes

Photo of Schematic illustration of the capillary photoelectrochemical water splitting process. Tivoli C. Gough, U.S. Department of Agriculture Forest Service.Schematic illustration of the capillary photoelectrochemical water splitting process. Tivoli C. Gough, U.S. Department of Agriculture Forest Service.Snapshot : Among current endeavors to explore renewable energy technologies, photoelectrochemical (PEC) water splitting holds great promise for conversion of solar energy to chemical energy. Light absorption, charge separation, and appropriate interfacial redox reactions are three key aspects that lead to highly efficient solar energy conversion. High porosity three-dimensional (3D) nanostructures, such as branched nanowire architectures and nanofiber networks, offer extremely large surface areas, excellent charge transport properties, as well as long optical paths for efficient light absorption.

Principal Investigators(s) :
Cai, Zhiyong 
Research Location : Forest Products Lab and University of Wisconsin Madison
Research Station : Forest Products Laboratory (FPL)
Year : 2016
Highlight ID : 980


Among all nanostructured three-dimensional (3D) morphologies, natural cellulose-based nanomaterials such as cellulose nanofibers (CNFs) have been attracting the most attention in nanomanufacturing because of their great abundance, low cost, degradability and biocompatibility. CNFs are composed of elementary cellulose fibrils that are extracted directly from natural plant resources. CNFs also demonstrate great adsorbability in both hydrophilic and hydrophobic materials. Thus, CNFs are considered an excellent template for creating functional, fibrous 3D nanostructures that possess extremely large porosity, such as silver fiber networks, nanotubular indium tin oxide sheets, and porous TiO2, ZnO, and alumina nanostructures. These CNF-templated nanostructures are very promising for the development of energy harvesting and storage devices. CNF-supported polyaniline nanocomposites showed an improved mass-speci?c capacitance in supercapacitor applications. In the Forest Service study, 3D fibrous TiO2 nanotube architecture was synthesized by atomic layer deposition of titania films over CNF templates. Because of the excellent hydrophilic properties of CNF films, a capillary PEC setup was developed to perform water splitting reactions outside of the electrolyte body, where electrolyte was supplied through nano- and micro-channels in the CNF film driven by capillary force. Enhanced reaction kinetics and higher efficiency were observed from the capillary photoelectricalchemical process.

Forest Service Partners

External Partners

  • Xudong Wang, University of Wisconsin Madison

Program Areas