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Topic: TiO2 doping  (Read 13945 times)

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Offline Timothy

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TiO2 doping
« on: July 24, 2012, 03:54:22 PM »
I'm working on trying to dope TiO2 to lower the band gap of 3.2eV. Anybody got any ideas. I have tried boric acid and copper sulfate by dissolving them in water then adding TiO2 followed by drying in an oven and then calcinating at 300˚C for 30mins. I am trying to get some titanium isopropoxide but I am at a dead end right now, does anybody have any ideas for successful doping of TiO2?

Offline vex

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Re: TiO2 doping
« Reply #1 on: August 27, 2012, 02:00:39 PM »
Have you checked any of the literature on this project? The lab that I work in does a fair amount of doping of TiO2, and there are several studies that have shown that the band gap can be decreased, especially using Nb and N doping. Reading some of these papers might give you a good place to start thinking. Good luck!

Signed,
The Competition  8)
University of Michigan Ph. D. Pre-Candidate, Inorganic Chemistry

Do or do not. There is no "try."

Offline Timothy

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Visible light semiconductors
« Reply #2 on: September 30, 2016, 04:07:04 PM »
Hi guys

Does anyone know how to activate these?? I have been trying for ages to achieve visible light reactivity of TiO2 doped with Ag towards a visible spectrum.

Also, I have CdS that I prepared from Cd(NO3)2.2H2O and thiourea which I irradiated with a Hg lamp.

I'm attempting to oxidise alcohols but nothing is working.

The recent reaction with the CdS had a 0.4% yield without the catalyst and 4% with.

Any advice would be greatly appreciated as I am stumbled at the moment with a huge amount of literature (that I have read and repeated) to say otherwise.

Many thanks

Tim

Offline Timothy

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Re: TiO2 doping
« Reply #3 on: October 01, 2016, 06:08:59 PM »
Hi The Competition

Are you still studying TiO2, I would really like to chat if you still are?

Many thanks

Tim

Offline Timothy

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Visible light semiconductors
« Reply #4 on: October 01, 2016, 06:13:39 PM »
Hi guys

Does anyone know how to activate these?? I have been trying for ages to achieve visible light reactivity of TiO2 doped with Ag towards a visible spectrum.

Also, I have CdS that I prepared from Cd(NO3)2.2H2O and thiourea which I irradiated with a Hg lamp.

I'm attempting to oxidise alcohols but nothing is working.

The recent reaction with the CdS had a 0.4% yield without the catalyst and 4% with.

Any advice would be greatly appreciated as I am stumbled at the moment with a huge amount of literature (that I have read and repeated) to say otherwise.

Many thanks

Tim

Sorry for the repeat if you're re-reading. I was wanting to approach our inorganic audience  ;D.

Offline Enthalpy

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Re: TiO2 doping
« Reply #5 on: October 01, 2016, 07:01:36 PM »
Someone asked about the same question here about his future research topic and there was literature on the Web.

If a comparison with semiconductors used for electronic devices is of any value, one standard method would be to replace a fraction of Ti or O atoms with bigger ones of the same valence. That would be Zr, Hf, Sn, Pb instead of Ti.
https://www.webelements.com/periodicity/molar_volume/

You're a civilized chemist, aren't you? I just wonder if melting the metals together and pulverizing them in an oxygen stream would make your mixed metals dioxide powder. Titanium burns so brutally that the other metal won't have time to escape. Once you have the powder, improve the crystals if needed.

Offline Arkcon

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Re: Visible light semiconductors
« Reply #6 on: October 01, 2016, 07:13:33 PM »
Sorry for the repeat if you're re-reading. I was wanting to approach our inorganic audience  ;D.

Then kindly don't.  I've merged your topics together into one thread.  People who can help, will help.  You've posted a esoteric topic, on a weekend.  You'll have to be patient.
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline Enthalpy

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Re: TiO2 doping
« Reply #7 on: January 31, 2017, 10:30:23 AM »
To burn the pre-alloyed Ti in O, liquid metal is hot, making the injector difficult.

Maybe an alternative would be to burn solid pre-alloyed Ti, in a thermal lance
https://en.wikipedia.org/wiki/Thermal_lance
that is, make a tube and optionally wires of the Ti alloy, blow oxygen through it, light the end.

The fineness of the alloyed TiO2 powder is more difficult to control: through oxygen speed, turbulence, wall and wires thickness...

If lighting the tube with a spark from a car battery, please be careful. Seriously.

Since Zr and Hf are difficult to separate, using both simultaneously to alloy Ti must be cheaper.

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