Honeycomb-shaped carbon nanotube supports for BiVO₄ based solar water splitting

Advances in the synthesis and assembly of nanomaterials offer a unique opportunity to purposefully design structures according to the requirements of the targeted applications. This paper shows a process to create robust 3D carbon nanotube (CNT) structures, which provide an electrically conductive support for nanoparticle coating. We describe a process to reliably fabricate robust honeycomb structures with walls made out of aligned CNTs. We present a design of experimental analysis of this fabrication process and discuss methods to coat these honeycombs with BiVO₄ for solar fuel applications. The proposed honeycomb structure allows for an efficient transport of electrons through the electrode, as well as an enhanced light-electrode interaction. Finally, we demonstrate that the developed CNT electrodes can survive harsh BiVO₄ synthesis conditions and can subsequently be used as photoelectrodes for solar water splitting.