Electrolysis with a niobium anode

[woelen]

I did an electrolysis experiment with 99.8% pure niobium metal as anode. I tried this, in an attempt to dissolve the very inert metal. My reasoning was that the metal either dissolves or allows all kinds of gases (such as chlorine) to be produced at the anode. The latter would be very nice, having a metal anode, which does not pulverize with electrolysis.

 

In reality, however, something really stunning happens. This is so weird that I decided to devote a web page to it. The experimental results can be read here:

 

http://woelen.scheikunde.net/science/chem/exps/niobium/index.html

[xeluc]

I did some research and came up with a website that describes in great detail what you have done. Also, it completly correlates with your experiments. Web Site

 

Some things to point out. As you said in the science madness forums, the oxide layer changes colors with higher voltages. The website says that many other colors excluding red can be made using even higher voltages. I find it very interesting where they talk about "paintbrush anodizing". I saw a thread by YT about this. Anyhow, yeah.

 

So basicly you were wondering on science madness as to what the blue color was. It's an oxide that changes color depending on thickness

[jdurg]

Yes indeed, you have successfully anondized niboium metal there woelen. This is done all the time as niobium is commonly used in body piercings and other jewelery as the metal can be anondized to virtually any color in the rainbow depending on the thickness of the oxide layer. In addition, as you were able to find out, the colored portion is remarkably resistant to chemical attack. So when used as body jewelery, one doesn't really have to worry about it getting destroyed over time. If you come into contact with something that can harm the colored oxide layer, the jewelery would be the least of your concerns.

[RyanJ]

This is done all the time as niobium is commonly used in body piercings and other jewelery as the metal can be anondized to virtually any color in the rainbow depending on the thickness of the oxide layer. In addition, as

 

DUDE, thats really cool, I love that blue colour.

 

So its actually the variable thickness of the oxide layer that causes the difference in color? Thats really interesting

 

Thanks for sharing it with us woelen, I'll see if I can get some niobium too try this in school, I do not yet have any electrolysis type equiptment setup

 

Cheers,

 

Ryan Jones

[woelen]

I did some research and came up with a website that describes in great detail what you have done. Also' date=' it completly correlates with your experiments. Web Site

[...]

So basicly you were wondering on science madness as to what the blue color was. It's an oxide that changes color depending on thickness

Xeluc, thanks for this information. This was something I did not know, so I learned a lot about niobium chemistry. I updated my webpage and added the information from your link to my page.

[jdurg]

Niobium is a neat little metal. I'm almost tempted to take my niobium coin and break it out of its air-tight capsule just to let it oxidize a little bit. It would make it more interesting as a metal, but having unoxidized niobium is something I'm happy to have.

[YT2095]

those colors remind me a little of steel when heat treated, it goes from silver to a gold and then a purple and then blue and ultimately back to silver again but very dull.

just out of curiosity, have you tried to see if it`s reversible at all, maybe as a cathode perhaps?

 

Excellent result though Woelen, keep it up!

[woelen]

Niobium is a neat little metal. I'm almost tempted to take my niobium coin and break it out of its air-tight capsule just to let it oxidize a little bit. It would make it more interesting as a metal, but having unoxidized niobium is something I'm happy to have.

I would suggest you keep the niobium in its nice container. Since three weeks Emovendo sells 30 grams of 99.8% niobium for $22 in the form of such sheets, as I show on my site. This is my source of the niobium. For my element collection I have a nice rod of the metal, but for chemistry experiments the sheets from Emovendo are very nice and affordable (although not really cheap).