To synthesize MXenes, I use the HF etching technique. My etching process is 24 hours, which means I started the reaction at 8 in the morning and it will end at 8 the next day. Is it necessary to immediately wash Mxene with water after completing my 24-hour etching process? Is it possible to degrade Mxene to leave it in the HF solution for a few more hours? Is it possible to store HF etched mxene without washing it?
When you are using HF (or in-situ production of HF), it is important to realize that all atoms in MAX phases are being attacked by HF. For Ti3AlC2, for example, the rate that Al is etched away is faster than Ti. This does not mean that the Ti is immune to HF, it just means that the rate of etching is slower.
What this means in practice, as you increase the HF concentration, you will have HF etching everything faster. This is why Ti3C2Tx produced with higher concentrations of HF has more defects. Article Atomic Defects in Monolayer Titanium Carbide (Ti3C2Tx) MXene
A similar thing is true with time. If you leave your MXene in HF, it will continue to react over time, leading to smaller flakes and more Ti defects.So, by leaving your MXene in HF longer, you are introducing more and more defects. For highest conductivity/flake size/stability, you want to have the minimum amount of etching time, as it leads to the lowest defects. Article Modified MAX Phase Synthesis for Environmentally Stable and ...
Article Ultralarge Flakes of Ti3C2Tx MXene via Soft Delamination
But, depending on your specific application, it may be better to have more defects.And please, remember that HF is quite dangerous to work with. Make sure to follow all safety protocols. Article Safe Synthesis of MAX and MXene: Guidelines to Reduce Risk D...
- Badges
- Science topic
- Similar topics
- Social Science
- Media
- Journalism