SYNTHESIS OF NANOCYRSTALLYNE SrTiO3 BY POLYSTYRENE ASSISTED SPRAY PYROLYSIS METHOD AND ITS APPLICATION FOR WATER SPLITTING PROCESS

• Main Author: TANUMIHARJA (NIM : 10210078); Pembimbing : Dr. Eng. Ferry Iskandar, RAYMOND
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/20432
• Institution: Institut Teknologi Bandung

Nanocrystalline strontium titanate (SrTiO3, STO) powders have been successfully synthesized via colloidal (polystyrene) templating spray pyrolysis method. The influences of pyrolysis temperatures (700, 800, and 900°C) and polystyrene ratios (0, 20, 40, 60%w/w of STO) with constant carrier gas (air) flow rate (2L/m) were <br /> <br /> <br /> investigated on the crystallinity, morphology, surface area, and hydrogen production rate of the resulting STO particles by X-ray diffraction (XRD), scanning electron microscopy (SEM), and nitrogen adsorption. STO samples were synthesized using titanium butoxide ((Ti(OC4H9)4) as titanium source, strontium nitrate (Sr(NO3)2) as strontium source, and citric acid (C6H8O7) as chelating agent. The first synthesis stage was to dissolve strontium nitrate and citric acid with 1:3 mol ratios in distilled water. The second was to dilute titanium butoxide in pure ethanol (Sr : Ti mol = 1:1), which then dripped slowly to the solution containing strontium nitrate and citric acid. Polystyrene then was added into the resulting solution with a certain ratio, stirred until homogeneous, and the final solution was spray-pyrolysed. The resulting particles showed that the sample synthesized at 700°C have black colour, while the other two have white, indicating that STO may have already formed. XRD results reveal that the formation STO synthesized at 800°C is yet to complete, at 900°C pure phase STO is obtained. Both STO synthesized at 800°C and 900°C have relatively same crystal size, which is 13.2 nm and 13.1 nm. SEM results reveal that STO synthesized at 900°C without the assistance of polystyrene template had spheres morphology with average particles size 1,1 &#956;m while the others had hollow spheres with average particles size 1,2 &#956;m. STO synthesized at 900°C without and with polystyrene were proceed to nitrogen adsorption characterization and analysed with BET method, showing that there is a significant increase of surface area from 16.6 m2/g to 51.6 m2/g. XRD results reveal that STO synthesized at 900°C with the help of polystyrene template have higher crystal size, which is 16.6 nm. The corollary of polystyrene ratios was studied toward hydrogen production, showing that there is a huge enhancement of water-splitting activity with the help of polystyrene. The optimum ratio is 40% polystyrene of STO with 822,2 &#956;mol/h hydrogen production rate while the one without polystyrene only had 33,3 &#956;mol/h. Based on the results of characterization technique which had been performed, it can be concluded that STO particles with good crystallinity, high surface area, and hollow sphere morphology have great water-splitting activity.