2 Preparation and characterization of SnO2,no animations
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The document summarizes research on enhancing the thermal stability of tin oxide hydrate (SnO2·nH2O) through phosphoric acid treatment. Tin dioxide has applications in areas like semiconductors, solar cells, batteries, and photocatalysis. The researchers prepared phosphorus-containing SnO2 samples using different phosphoric acid concentrations and characterized their structural and surface properties using techniques like thermogravimetric analysis, X-ray diffraction, and UV-vis spectroscopy. The phosphoric acid treatment was found to increase the thermal stability of SnO2 by controlling phosphate coverage on the tin oxide hydrate particles and reducing sintering at higher temperatures. Samples with low phosphate content modification of SnO2 exhibited
2 Preparation and characterization of SnO2,no animations
- 1. Preparation and characterization of SnO2 nanoparticle of enhanced thermal stability: The effect of phosphoric acid treatment on SnO2 · nH2O Laszlo Korosi, Szilvia Papp , Vera Meynen, Pegie Cool, Etienne F. Vansant , Imre Dekany Colloids and Surfaces A: Physicochem. Eng. Aspects 268 (2005) 147–154 Sameh Hamzawy MESC9
- 2. Outline Introduction Experiment Results and discussion Conclusion
- 3. Enhancement the thermal stability of tin oxide hydrate ( SnO2.H20) by the phosphoric acid treatment. Tin dioxide has many motivated application, such as n-type semiconductor, DSSC, Li-batteries, photocatalysts,…etc. Analyze the structural and surface properties of phosphorus containing SnO2 using different techniques. Introduction
- 4. Preparation of a reference sample of tin hydrogen phosphate (Sn(HPO4)2 · nH2O). The preparation of P-SnO2 was performed in two stages: 2- (SnO2.H20 ) was treated with different concentrations phosphoric acid solution to prepare samples with different (P:Sn ) molar ratios. Experiment 1- Tin oxide hydrate was prepared by the hydrolysis of tin(IV) chloride.
- 5. Weightloss(%) Temperature ( ᴼC) Fig.1: Thermogravimetric curves of SnO2, Sn(HPO4)2 and P-SnO2/3.4 dried at 80◦C. The TG curve shows the total weight loss for : Sn(HPO4)2 ∼ 15% up to 800 ◦C Sn(HPO4)2 · nH2O → Sn(HPO4)2 + nH2O Sn(HPO4)2 → SnP2O7 + H2O P-SnO2/3.4 ∼ 11%. up to 800 ◦C Results and discussion SnO2 ∼ 14% up to 800 ᴼC.
- 6. Fig. 3. XRD patterns of SnO2 with different phosphate contents after 800 ◦C calcination. Fig. 2. DRIFT spectra of (a) different P- SnO2 after drying at 80 ◦C. Intensity
- 7. Fig.4(b)P-SnO2/1.1 sample at different calcined temperatures. Fig. 4(a) XRD patterns of (a) pure SnO2 at different calcined temperatures. Intensity
- 8. Fig.5. XRD patterns of different phosphate content tin dioxide and cubic tin phosphate calcined at 1000◦C. Fig.6. UV–vis diffuse reflectance spectra of different P- SnO2 samples, dried at 80◦C.
- 9. Fig.7: Schematic illustration of the effect of phosphoric acid and heat treatment on SnO2 · nH2O.
- 10. SnO2 of enhanced thermal stability was prepared. The phosphate coverage of tin oxide hydrate particles can be controlled via the phosphoric acid concentration. The extent of sintering of SnO2 is reduced and it is proportional to phosphoric acid concentration, At low phosphate content modification of SnO2 has high thermal stability in addition to the photocatalytic activity. Conclusion
- 11. Thank you for your attention
Editor's Notes
- #4: - Tin dioxide is a widely used and intensively studied n-type semiconductor. in addition to DSSC, Li-batteries, photocatalysts, and gas sensors.
- #5: - Modified tin dioxide (P-SnO2) -Preparation of a reference sample of tin hydrogen phosphate (Sn(HPO4)2 · nH2O) from tin(IV) chloride and phosphoric acid using molar ratio of 1:2.
- #6: - The TG curve of Sn(HPO4)2 /800 ◦C shows that the total weight loss ( ∼ 15%)
- #7: - diffuse reflectance infrared Fourier transform (DRIFT) Fig2: The increase of the P-O vibration intensities thus occurs on the account of Sn–O bond intensities. This suggests that the phosphate does not adsorb on the surface of the original SnO2 particles, but rather it infiltrates and reacts with the bulk of SnO2, forming a thicker or thinner coating P-SnO2 phase. In this way, the size of the remaining pure SnO2 core decreases. - Fig3 : X-ray diffraction patterns of SnO2 and P-SnO2 samples calcined at 800 ◦C are presented. The intensity of the characteristic (1 1 0) and (1 0 1) tin dioxide reflections (at 2 θ = 26.5◦ and 33.7◦, respectively) decreases and the width of the peaks increases with increasing phosphate content.
- #8: Calcination experiments reveal that phosphorous acid treatment leads to the increase in the thermal stability of SnO2. The SnO2 phase of the modified sample does not undergo structural changes at 550◦C, while the pure SnO2 sample crystallizes at this temperature.
- #9: Fig. 6. UV–vis diffuse reflectance spectra of different P-SnO2 samples, dried at 80◦C.
- #10: - The change in particle structure is due to the combined effect of heat treatment and increasing phosphoric acid concentration.
- #11: SnO2 of enhanced thermal stability was prepared by phosphoric acid treatment of tin oxide hydrate. The phosphate coverage of tin oxide hydrate particles can be controlled via the phosphoric acid concentration. - the extent of sintering is reduced and it is inversely proportional to phosphoric acid concentration, because the tin phosphate shell formed on the surface of the SnO2 particles inhibits crystal growth during calcination. - At this low phosphate content, the surface is only loosely covered by phosphate so that it can be supposed that photocatalytic or sensor applications specific of tin dioxide remain possible.