I have tried cleaning the NWs powder using ultrasonic bath with many solvents such as acetone, ethanol, deionized water (DI H2O), and isopropanol (IPA), methanol, each of these done separately and filtered afterward with cool ID H2O.

Also, I washed and filtered NWS with 8L of boiling ID water.

also, I used different substrates like glass, carbon tape.

also, i used ethanol, and then ID H2O separately with using centrifuge.

However, none of these methods have successfully removed the contamination, as shown in the SEM image of the NWs mixed with contaminants.

What alternative approaches or techniques can be employed to achieve successful decontamination in this case?