Unravelling camphor mediated synthesis of TiO2 nanorods over shape memory alloy for efficient energy harvesting

We demonstrated a cost-effective and scalable chemical vapor deposition (CVD) process for the production of high quality and dense rutile titanium dioxide nanorods (R-TiO<inf>2</inf> NR) based on camphor (Cinnamomum camphora) decomposition over shape memory alloy (nitinol). The topography of the camphor-based R-TiO<inf>2</inf> NR was studied under field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM) which revealed high coverage of R-TiO<inf>2</inf> NR over the substrate. The phase purity of R-TiO<inf>2</inf> NR was established by X-ray diffraction measurements performed at different camphor concentrations and substrate temperatures. Raman spectroscopy and X-ray photoelectron spectroscopy confirmed the chemical and the elemental composition of the nanorods grown over nitinol, which suggest the formation of high-quality R-TiO<inf>2</inf> NR. Further, R-TiO<inf>2</inf> NR was used as photoanode in 1 M KOH solution for efficient energy harvesting application by indicating a high photocurrent density of 550 µA/cm² at 1.23 V vs RHE (reversible hydrogen electrode), indicating excellent light trapping mechanism with efficient charge separation and extraction. The proposed CVD process is a suitable method for large scale production of R-TiO<inf>2</inf> NR over nitinol, which can be potentially employed in sensors and various other biomedical applications.