Hydrothermal synthesis and photoluminescence properties of SnO₂ nanowire array and pinecone-like nanoparticles on ITO substrate

The SnO₂ nanowire array and pinecone-like nanoparticles were synthesized on the indium tin oxide (ITO) substrate via a simple hydrothermal process. The microstructure and morphology of the samples indicated that both nanowire array and pinecone-like nanoparticles were composed of rutile SnO₂ nanowires. Furthermore, a reasonable growth mechanism of SnO₂ nanowire array and pinecone-like nanoparticles was proposed, and the molar concentration ratio of NaOH to SnCl₄ of the precursor solution played a key role in the morphological evolution. Finally, the photoluminescence properties and the ultraviolet-visible absorbance spectrum were investigated. The band gap of SnO₂ nanowire array was about 3.43 eV, which was consistent with the emission peak of PL spectrum.