The cuprous oxide is very important material because of their unique properties comparing with other bulk counterparts, so its uses in various fields of technology. It is a p-type narrows band gap semiconductor and place into transition metal. It has large number of application in different field due to its monoclinic structure and its different properties such as, high stability, photovoltaic properties, super thermal conductivity and antimicrobial activities. Because of different properties cuprous oxide can be use many technological field e.
g. gas sensor, active catalyst, solar cell and magnetic recording media.
Literature information numerous methods for the synthesis of Cu2O nanoparticles such as the thermal oxidation, activated reactive evaporation, spray , laser ablation, liquid phase synthesis. The summery of synthesis method, conditions, temperature, particle size, key finding in perspective with the above mentioned method is provided below. This shows that generally liquid chemistry techniques are best for synthesis of Cu2O nanoparticles and nanostructure.
We effectively synthesis cuprous oxide nanoparticles by subsequent (A) Gau , (B)Bai and (C) Huang methods exactly by following their synthesis procedure as report in the literature and prepared four different Cu2O sample namely A,B, C and D .
Out of which as A,B and C samples corresponds to method (A),(B) and (C) respectively. All the methods are in brief explained below as.
Herein process, copper sulphates penta hydrate (0.1ml) L-ascorbic acid (0.1ml) polyethylene glycol (MW600) and sodium hydroxide (0.5ml) were use as reagents. 4ml solution of copper sulphate penta hydrate were mixed by 1ml of PEG solution and into the consequential 1ml solution were added .
On stirring the resulting solution for 5 minutes to complete the reaction to give yellow-orange color solution of Cu2O nanoparticles. It was almost immediately after centrifuged two times at 6000rmp for 30 minutes by dispersing in distilled water in a centrifuged machine to take away excess PEG..
At first 0.25mmol (0.05g) of the cupric acetate and (0.005) of polyvinyl pyridine were dissolved 100 ml of distilled water. In this solution then 20ml aqueous solution of hydroxide was at normal temperature below dynamic rousing to acquire a blue suspension. In this blue suspension 15ml aqueous solution of ascorbic acid 0.75mol (0.32g) was then drop wise added at a rate of 3drop/second under vigorous rousing for 30 minutes to form reddish suspension was latter centrifuged at 4000rmp for 15 minutes. The obtained result was washed with three times to get Cu2O nanoparticles in colloidal dispersal appearance which was labeled as model B previous to make the most of further categorization.
First of all we take, 0.1 ml (0.1M) copper chloride were mixed together with 9.55ml of double distilled water to which 0.2ml of 1M of sodium hydroxide solution were added while stirring at normal temperature. Then this goes in to bluish solution to which 0.087g of sodium doddery sulphate was again added while stirring. Finally 0.15ml of 0.2ml hydroxylamine solution was quickly added while shaking and getting solution for 2 hours. At the last, centrifugation at 5000rpm with subsequent cleaning is distilled water leads to Cu2O sample.
The all sample of Cu2O is prepared the above methods were dispersed in double distilled water and these are manganese in the separate bottles for more characterization. The synthesis of Cu2O was confirmed on the basis of absorbance spectra measurements done by using spectroscopy. Generally the absorbance peak is in the nearest neighborhood of ?= 490nm. The study of phase stability was also formed by monitoring the UV-VIS absorbance characteristic as a function of ageing period.
As shown in the figure A, B, C and D sample of Cu2O nanoparticles. The typical absorbance of A, B, C and D sample shows the peak at ?= 490nm ?= 503 nm, 484 nm, 462 nm and 494 nm. The reason of absorption peak is due to the plasma resonance excitation of copper atom on the surface of nanoparticles. This reports shows the character tic absorbance peak for the Cu2O is generally observed in the nearest of ?= 490nm. The blue shift were observed in the typical absorption peak at ? = 462.5nm of sample C and ?= 484nm of sample B may b distributed to decreased in the particles size. The measurement of the band gap was done by using formula E_g= hc/n? where c is the speed of light, h is Planck’s constant and is ??the wavelength for the typical absorption peak. The direct band gap values were notices to be increased from 2.47Ev, 2.51eV, 2.56eV and 2.68eV for A,D,B and C sample respectively .These are higher than theoretical direct band gap due to nano size which leads to quantum incarceration effect .
After the experiments it is seem that Cu2O phase were not stable and shoes ageing with time for all the sample. Therefore the phase constancy as synthesized sample A, B, C, D were studied over an ageing period by noticing the UV-VIS absorbance spectra.
The summary of phase stability performed for A, B, C, D sample
Ageing period in day Absorption peak position after ageing Ref
[A] A 50O 502 10 760 25
[B] B 484 484 07 605 26
[C] C 490 462.5 12 641 27
[D] D – 494 15 564 27
Graph 01- UV-VIS Spectra of A,B,C,D
Graph 02- UV-VIS Spectra of B (a) as synthesized and (b) after seven days
The simple, liquid phase method for synthesis of Cu2O nanoparticles at normal temperature (room temperature) are reviewed and reworked to view the stability to repeatedly synthesis the stable nano Cu2O colloids. The method lead to successful synthesis of Cu2O nano particles; however the synthesized Cu2O colloidal suspensions were found to be unstable and underwent a phase change to a more stable Cu2O phase. The result shows the instability of reviewed methods to synthesize stable Cu2O nano colloidal. Therefore, this demands for a simple, room temperature methods for synthesis of Cu2O nano particles which stable for longer ageing period.
👋 Hi! I’m your smart assistant Amy!
Don’t know where to start? Type your requirements and I’ll connect you to an academic expert within 3 minutes.get help with your assignment