After a few minutes, Chen Zhengping, who finally finished the experiment in his hands, took off his white coat and plastic gloves and walked over.
"How's it going? Did you find anything new?"
Chen Zhengping asked curiously. He asked Xu Chuan to come over to help just because he wanted to give it a try.
Needless to say, his disciple's mathematical ability, which can prove world-class conjectures, must have surpassed most mathematics professors.
At least in areas such as functional analysis, spectral asymptotics of elliptic operators, inverse spectral problems and fractal drum theory, he has surpassed more than 90% of mathematics professors.
But he never thought that Xu Chuan would discover it so soon.
After all, mathematics and materials are two almost completely different fields. Although materials science requires some mathematics, it does not require very advanced mathematics.
On the contrary, modern materials discipline pays more attention to the study of various types of materials and the interpenetration and comprehensiveness between them.
This requires material developers to be familiar with the characteristics of each material and how these materials will change during the experiment.
Chen Zhengping nodded and rubbed his temples with a headache: "I didn't find it here either. So it seems that the abnormality in the previous data should be related to the method or experimental procedures?"
"For example, the reducing agent may have impurities? Or mismatch or something?"
Xu Chuan added a very layman's remark, which instantly aroused the rebuttal of the master Xiong Fan Pengyue.
In other words, when processing tungsten diselenide nanosheets by liquid phase exfoliation, there is no initial material loss problem.
Can a small peak segment lower the yield rate by ten percentage points?
Chen Zhengping thought for a while and said: "Well, find me two previous experimental data, the experimental data of chemical vapor deposition method and liquid phase peeling method."
What he had in hand was experimental data on the peeling off of tungsten diselenide nanosheets by liquid phase exfoliation.
Is this disciple's vision in mathematics really so vicious?
Taking the calculation paper and experimental data from Fan Pengyue, Chen Zhengping first looked at the energy spectrum peak segment pointed out by Xu Chuan. After confirming that this was indeed an error that they had previously ignored and thought was a normal reaction, he looked at the paper.
calculated data on.
The meaning is a bit crude, but the principle is correct.
"Okay." Fan Pengyue nodded, walked to the computer, called up the previous experimental data, and connected it to the printer in the laboratory's printer room.
The yield rate was 48.32%. This value made him frown.
Xu Chuan put down the experimental data in his hand and added: "I just looked at the data and noticed that the data in the solvothermal method seemed to have a reducing agent added. Could the problem occur in the reducing agent?"
Judging from the data, the yield of tungsten diselenide nanosheets processed by liquid phase exfoliation can be as high as more than 60%, which aroused his interest.
The so-called liquid phase peeling method is to disperse the raw materials that need to be peeled off into a specific solvent or surfactant; then use ultrasonic energy or other means to directly peel off single or multi-layer raw materials from the surface, thereby maintaining the intact shape.
dispersions and monolayer raw materials with different appearance and properties, which can then be deposited in a variety of environments and on different substrates.
"As for impurities, it is not difficult to purify hydrogen. Using laboratory equipment, we can purify hydrogen to more than 99.99%, so impurities can basically be eliminated."
However, what is interesting is that Xu Chuan did not find the same anomaly as before in the experimental data of peeling off tungsten diselenide nanosheets by liquid phase exfoliation.
"How's it going? Did you find anything?"
On the side, after reading the experimental data in his hands, Chen Zhengping looked at Xu Chuan and asked.
But the data in front of him was clearly there, and he fell into silence again.
Isn’t this too big of an impact?
"Well, that's it." Fan Pengyue nodded to confirm.
Xu Chuan nodded, took the experimental data and started reading it.
Xu Chuan shook his head and said: "No, I have read the data in my hand three times and found no abnormal points. I calculated the yield rate and it can reach more than 60 points."
Chen Zhengping took one copy and handed the other to Xu Chuan: "Help me check whether there is a similar situation in the data you have."
Hearing this, Fan Pengyue smiled bitterly and said, "You don't understand. Tungsten diselenide is different from natural minerals such as graphite and molybdenum disulfide. Currently, it can only be prepared through artificial synthesis."
After thinking for a long time, Chen Zhengping looked up at Fan Pengyue and asked: "The method used in this set of experimental data is the solvothermal one-step synthesis method, right?"
Xu Chuan stared at the experimental data in his hand, touched his chin and thought, the data from two different experimental methods told him some different answers.
"This is impossible. The reducing agent I use is hydrogen. This is the most suitable reducing agent for tungsten diselenide and has the highest efficiency and film production."
"Interesting, it seems that the reason why the one-step synthesis of tungsten diselenide nanosheets by solvothermal method is so low does not seem to be entirely caused by the van der Waals force. In the early stages of the experiment, there must be other factors that affected the one-step synthesis of tungsten diselenide by solvothermal method.
Law."
"I don't know about this."
Xu Chuan shrugged and said: "I don't know about that, but the efficiency of preparing tungsten diselenide nanosheets using this method is indeed not high at present. Maybe we can try another method?"
This unscientific.
Originally, he was going to spend a day or two explaining tungsten diselenide nanosheets and then ask Xu Chuan to help with the analysis. Unexpectedly, he would make a new discovery when he came in.
To put it simply, tungsten diselenide is put into a special solvent, first broken into pieces, and then deposited into nanosheets.
After a while, two sets of experimental data were printed out.
And if calculated based on this yield rate, they have made no progress at all in the preparation of tungsten diselenide nanosheets in the past two or three months, and can even be said to have regressed.
"Furthermore, the soluble selenium salt used to synthesize tungsten diselenide is toxic, and the green synthesis method is single, basically limited to solid-phase synthesis of W-Se. Existing processes generally need to be carried out in CVD tube furnaces, which are very expensive.
, and high-end equipment is monopolized by foreign countries, which is not conducive to domestic large-scale industrial production."
"So the current price of tungsten diselenide is quite expensive in China, and the solvothermal method is among the best in our research and development experiments."
"Because its process is simple, the raw materials are green and environmentally friendly, the cost is low, the reaction conditions are mild, and the obtained tungsten diselenide nanosheets have high crystal quality, uniform size distribution and high specific surface area, and the thickness of the nanosheets is below 10nm
.”
"This is also the key direction of our research. If we can succeed, it will create a vast market with huge prospects, worth billions every year. The most important thing is to break the foreign monopoly, so we can't do it so easily.