Fabrication of high purity silica precipitates from quartz sand toward photovoltaic application

The development of renewable energy is becoming a crucial aspect because fossil fuels are non-renewable energy and will run out in the near future. Since Indonesia is in the equator area which gets sunshine throughout the year, solar cell is one of the renewable energy which is very promising as renewable energy. The obstacle to develop solar cell is the high cost of solar panel. Therefore, new technology to produce silica with high purity is important to be performed in order to be used as material in making solar panels. Here we fabricated high purity silica precipitates from quartz sands from Kendawangan, West Kalimantan. We fabricated silica precipitated by roasting quartz sand and then dissolving the sodium silicate into boiling water followed by leaching, precipitation and repeatedly washing using hydrochloric acid. The content of SiO₂ of atomic absorption spectroscopy of quartz sand from Kendawangan contains SiO₂ of 99.2% and the remaining trace elements are impurities. The roasting process was conducted using sodium carbonate with the comparison of quartz sand: sodium carbonate = 55:45 (% ratio) at 1.200 °C for 2 hours obtaining sodium silicate crystal. The final result of silica precipitates obtained in this research showed that the silica precipitates has very high purity with content of SiO₂ up to 99.99%. This successful result will contribute for domestic industry which can provide high purity silica precipitates for material source of solar grade silicon in photovoltaic device.