Synthesis TaON nanotubes by annealed and nitrided tantalum oxide nanotubes. Tantalum oxide nanotubes was synthesized by traditional anodization method. Characterize TaON nanotubes' physical property by XRD (X-ray diffraction) and SEM (scanning electron microscope). TaON nanotubes' optical and photoelectrochemical properties were also be characterized

Dhabarde, Nikhil R.

Khanal, Vijay

Yue, Wenxue

University of Nevada, Reno ScholarWorks Repository

    Figure 7. Chronoamperometry (j/t) of anodized and untreated Ta foil ● 3-fold increment in photocurrent is observed after anodization           Figure 8 Electron impedance spectra (EIS) of anodized Ta (followed by annealing at 500℃) in light and dark conditions ● Lower radius ofcurvature observedunder illumination in EIS shows better charge transport achievedafter anodization.                  Chart 1. Anodization and annealing . Figure 1.Schematic diagram of anodizing cell. Polish Ta foil Sonicate in HCl Sonicate inDI water 5 min 5 min Anodize Taby changingtime andvoltage Sonicate inacetone Ta foil Ta2O5 NH4OH (g), 800°C, 20 mins Annealingat 5000C/N2 25°C 25°C Ta2O5 TaON Chart 2.Nitridation.     Figure 5. X-ray Diffraction(Ta2O5 was anodized at 15V/20min and annealed).         Figure 4. SEM of TaON. Figure 3 . SEM of Ta2O5.   Figure 2. EDS of TaON.    Figure 6. UV-vis Absorbance spectra of Ta2O5 and TaON. Synthesis of Ta2O5 by Anodization and TaON by Nitridation and their Characterization Wenxue Yue,1,2 Vijay Khanal,1 Nikhil R Dhabarde,1 Vaidyanathan (Ravi) Subramanian1 1University of Nevada,Reno; 2Shanghai University INTRODUCTION FUTURE WORK RESULTS REFERENCES ABSTRACT CONTACT <Vaidyanathan (Ravi) Subramanian> <University of Nevada, Reno> Email: ravisv@unr.edu Phone: +1   (775)741-8250 <Wenxue Yue> <Shanghai University> Email: yue.wenxue@qql.com Phone: +86 188-1761-3919 +1   (775)437-8384 Tantalum oxide (Ta2O5) was synthesized by an anodization method, and single phase tantalum oxynitride (TaON) was prepared by a novel nitridation method developed in our lab. SEM images of the sample surfaces have been obtained. The synthesized samples were further characterized using X-ray diffraction (XRD) and UV-vis absorbance. The novel nitridation approach reproducibly yields single phase TaON. Preliminary studies on the oxide using chronoamperometry (j/t), linear sweep voltammetry (LSV), and electron impedance spectroscopy (EIS) have been performed. Comparison of the Ta2O5 and TaON are in progress. ● ● ● Anodization of Ta was observed to yield Ta2O5 phase TaON was synthesized by simplified nitridation of Ta2O5. 3-fold increment in photocurrent by Ta2O5 was observed. ● ● Optimize voltage and time to synthesis single phase Ta2O5 and TaON nanotubes. Examine the application of TaON nanotubes as visible-light driven photocatalysts. ●●●● Anodization of Ta foil is a approach to synthesize 1-D Ta2O5 nanotubes However, Ta2O5 is active only under UV radiation (large bandgap 3.9 eV, < 5% UV content in solar spectrum) Nitridation of Ta2O5 can be used to synthesize its nitrogen derivatives with lowered bandgap allowing for utilization of wider solar spectrum2 Our aim is to make TaON nanotubes using a  simplified nitridation method recently devised in our lab.    1. Nageh K A, Xinjian J F, Craig A G. Chem. Mater. 2008, 20, 6477–6481 2. Vijay K, Rowshanak I, Sebastian F, et al. Journal of The Electrochemical Society.166 (5) H3294–H3299 (2019) 3. Subarna B, Susanta K M, Mano M. Chem. Commun., 2009, 7137–7139 Photoelectrochemical (PEC) Properties ●  ●A technique used for phase identification of a crystalline material. Ta2O5 and TaON phase formation was confirmed by XRD X-ray Diffraction (XRD) METHODS ●● SEM can be used to observe surface topography of the sample.  The morphology of surface has changed after nitridation. Scanning Electron Microscopy (SEM) ●  ●EDS is used for analysis of elemental composition. EDS of  as-nitrided sample confirmed that  Ta, O, and N are the only constituents. Energy-dispersive X-ray Spectroscopy (EDS) ● ● ● I would like to acknowledge the Undergraduate Research Office for their overall support. I am grateful to my advisor Dr. Vaidyanathan (Ravi) Subramanian and members of the SOLAR lab. I would also like to acknowledge the support from Zachary Karmiol and Dr. Misra for the SEM images. ACKNOWLEDGEMENTS ● ● UV-vis spectroscopy quantifies optical absorbance both in ultraviolet and visible regions. As-synthesized TaON shows significant red-shift ( λonset~ 320nm for Ta2O5 & 550 nm for TaON) in absorbance. Ultraviolet-Visible (UV-Vis) Spectroscopy CHARACTERIZATION 

Synthesis of Ta2O5 by Anodization and TaON by Nitridation and their Characterization

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