Photoelectrochemical cells by design: 3D nanoporous CdO-CdSe architectures on ITO

We report on the synthesis of CdO-CdSe nanoporous architectures from porous CdO architectures by a controlled solution anion exchange method. Monolithic CdCO3 micron sized crystals synthesized in the first step were decomposed by calcination to evolve CO2 to form porous CdO crystals, having a similar outer shape but with a tailored internal nanostructure. Controlled Se2- ion exchange with CdO crystals yielded CdO-CdSe architectures with tunable composition and optoelectronic properties. Pearson's acid-base concept is used as a guiding principle for controlling the morphology and composition of the formed architectures. The photoelectrochemical properties of the system comprising CdO-CdSe architectures were investigated at various stages of ion exchange intervals. CdO-CdSe architectures on indium tin oxide (ITO) is a promising photoelectrode with excellent photovoltaic properties exhibiting a short-circuit current density of 7.36 mA cm(-2) under 1 Sun illumination.