Would anyone mind to help and suggest me a way of solving this issue, please? Could it be a problem related to washing the synthesized sample or something else? I would be grateful for the help.

There are a number of factors that can affect the quality of crystalline nanoparticles/nanowires, including:

• The choice of starting materials. The quality of the starting materials will have a direct impact on the quality of the final product. For example, using high-purity starting materials will help to produce nanoparticles/nanowires with fewer defects.
• The synthesis method. The synthesis method used to produce nanoparticles/nanowires can also affect their quality. Some methods, such as chemical vapor deposition (CVD), are more likely to produce high-quality crystalline nanoparticles/nanowires than other methods, such as sol-gel synthesis.
• The growth conditions. The growth conditions, such as temperature, pressure, and time, can also affect the quality of crystalline nanoparticles/nanowires. For example, growing nanoparticles/nanowires at a high temperature can help to reduce defects.
• The post-treatment. Post-treatment, such as annealing, can also improve the quality of crystalline nanoparticles/nanowires. Annealing can help to remove defects and improve the crystallinity of the nanoparticles/nanowires.

Here are some specific tips for getting better quality crystalline nanoparticles/nanowires:

• Use high-purity starting materials.
• Choose a synthesis method that is known to produce high-quality crystalline nanoparticles/nanowires.
• Control the growth conditions carefully.
• Consider post-treatment, such as annealing.
• Tailor the properties of the nanoparticles/nanowires to the specific application.

By following these tips, you can improve the quality of your crystalline nanoparticles/nanowires and achieve the desired properties for your application.

Dear Vishnu, thank you for nice explanation for achieving the high quality crystalline NPs.

If you follow the methods reported but still cannot obtain the high quality crystalline NPs, there are two main reasons possibly cause it: 1) the oven or furnace temperature control is not accurate, this is especially the case if your instruments are very old. You need to calibrate it. It happens to my MOFs or nanoceria. 2) the methods you use are not reliable and the repeatability is bad. Many papers, even in top journals have this issue. My suggestion is to find one paper with extremely high citation that published in very good journals. If it still failed after you try these two methods, I would suggest you to directly reach out to the corresponding author of the paper, show your results and confusion about their method, normally they would reply to you quickly and give you some tips. Sometimes, even you ignore a very small step, it will ruin your synthesis. I hope it is helpful.

I would like to answer this question.

1) Please grow the nanowires (with better crystallinity) by using PVD methods especially E-beam evaporation.

2) Do post-annealing at least up to 150degC in a vacuum to get highly crystalline nanowires.

I am attaching one of the papers which you can refer for your problem.

Article Growth of ZnO nanowires using thermal oxidation process

Thanks.

Pramanand Joshi I'd try post heat treatment to say 400 C as an experiment to see if your XRD peaks get more narrow indicating more crystalline material. What's the problem in having an amorphous preparation? In some situations this can be advantageous.

@ Alan Kindly, do post annealing in vacuum not in ambient condition.

And answer to your 2nd question Plz deposit the materials at just the melting point of same material (Slow deposition), don't put high voltage/current at the deposition time.

Hope it will help.

If the broad peak observed in the XRD pattern does not arise from impurities but instead signifies a lower product quality, several solutions can be pursued:

Thank you so much everyone for valuable suggestions. They would be helpful in many ways.