What’s in this article?
This article details the synthesis of silver-doped titanium dioxide nanotubes by electrochemical anodization. These nanotubes were characterized to determine its morphological, chemical, and crystallographic properties. They were then used as photo-electrodes in a photoelectrochemical reactor and its photoelectrocatalytic performance was investigated against the degradation of a common dye – Acid Orange 52.
What are Titanium Dioxide Nanotubes (TiNTs)?
Titanium dioxide nanotubes are porous nanostructured materials with a one-dimensional geometry and ordered morphology. They are synthesized electrochemically through anodization of a titanium substrate in an electrochemical cell or hydrothermally under mild and inert environment.
What is doping?
Doping is the addition of impurity/ies to the crystal structure of a material aimed to modify its electronic, optical, or structural properties. In the field of semiconductor photocatalysis, it is usually done to improve visible light absorption by introducing impurity energy levels (IELs) in the electronic structure of photocatalysts, hence effectively narrowing their band gap. This is important to lower the energy requirement for the photoactivation of semiconductor photocatalysts such as titanium dioxide.
Titanium dioxide is a wide band gap semiconductor (3.2 eV). When used as a photocatalyst, it becomes limited to the ultraviolet region of the solar spectrum because of its high energy requirement for photo-activation. Doping with transition metals such as silver narrows the band gap of titanium dioxide, hence making it catalytically-active not only in the UV region but also in the visible light region. This is important to reduce the costs associated with photocatalytic water treatment processes.
What is photocatalysis?
Photocatalysis, in general, is an advanced oxidation process (AOP) where a light source photo-activates the electron in the valence band of the photocatalyst, hence creating photo-generated electron-hole pairs which reacts with water molecules and dissolved oxygen to form various free radicals. In water treatment, these free radicals are consumed instantaneously for the degradation of various organic compounds.
This conference paper was presented at the 7th International Conference in Material Science and Engineering Technology held at Beijing, China last October 2018. Researchers in material science and engineering gathered and discussed various emerging technologies in the field. The original article was published in the conference proceeding “Materials Science Forum” by TransTech Publications and can be viewed at http://bit.ly/MSF-Silver-doped-TiO2-Nanotubes.
Currently, we are working on investigating other doped titanium dioxide nanotubes for photocatalytic and photoelectrocatalytic applications. We are also performing theoretical studies to determine their electronic, optical, and structural properties from first-principles calculations.
A (not-so-small) feat
Being an early-career researcher has too many challenges. At first, you don’t know where your research will lead you. But I guess one of the most rewarding feats of doing research is that you are able to contribute to the advancement of your chosen research field.
Herein, I am proud, in the very least, to have written my first conference article. While this is a small feat compared to publishing in major journals, I still believe that this is one step closer for me to eventually get there. There’s a long way to go, a lot new papers to write, and a lot of rejections to expect, but most importantly, we should cherish these small feats because huge things are made out of tiny building blocks. And this paper is a motivation for me to soar deeper in the complex world of academic research – all for mankind.