Capturing Solar Energy with Clay and Mangosteens

Clay is not only can be brick or pottery. In the hands of Is Fatimah, sticky clay materials also may be generating electricity from sunlight. Of course not just any clay she uses. Fatimah create titania clay colored with mangosteen skin pigment.

Is Fatima is one of the few experts clay in Indonesia. She knew the particulars of quality clay from every region in Indonesia. Chemistry doctorate from the University of Gadjah Mada is concerned with the study of chemical material in the clay for almost 14 years. Fatimah know that the best quality of clay is low quartz, such as clay from Boyolali region, smooth and strong adhesive power. Too much quartz mixture is create less clay loam and coarse grains. "Soft clay was pottery makers favored," she said.

DR. Is Fatimah. (Picture  from: 
KORAN TEMPO 4094)

Interest to examine the clay has been felt by the material's chemistry lecturer from the beginning she taught at the Mathematics and Natural Sciences Faculty of Indonesian Islamic University (Fakultas Matematika dan Ilmu Pengetahuan Alam-Universitas Islam Indonesia/FMIPA-UII) in 1998. "The results of the research could be useful clay," she said on December 18, 2012.

Clay is the weathered silica rock by carbonic acid. When mixed with water, this material will be sticky and clay. It is easily shaped when wet and hard when dry, making this material used as bricks, tiles, and pottery. High quality clay has smooth and strong adhesive power, it can be mixed with titanium dioxide (TiO2), which is widely used as a raw material of synthetic dyes. By mixing clay and titanium dioxide, Fatimah get new material called titania clay, are smooth and like flour. "These experiments are the manufacture of titania clay through 17 papers published in international journals," she said.

Since 2010, Is Fatimah was busying herself with titania clay in chemical laboratories FMIPA UII. Busyness is delivered towards the discovery of the practical benefits of titania clay. "Can be used as a third-generation solar cells," said Fatimah. It uses Dye sensitized Solar Cell (DSSC) technology, which is an alternative to the previous technology, the use of crystalline silica and thin films.

Fatimah's solar cells made by mixing titania clay with purplish red pigment from the skin of mangosteen. The pigment serves to bind more sunlight. To obtain a purplish red pigment, the skin of the mangosteen dried and turned into powder and extracted. Mangosteen skin powder is mixed with ethanol and then evaporated back into powder. To color the clay material, the powder given ethanol again.

Titania clay dispersed on conductive glass layer covering the basic components of a solar panel. Other conductive glass cover that has been earlier sprinkled with a layer of titania clay. "When exposed to light, the cells that produce electricity," said Fatimah.

Dye Sensitized Solar Cell from Mangosteen Clay. (Picture from: KORAN TEMPO 4094)

In 2011, Fatimah's research received financial support amounting to Rp. 70 million from the L'Oreal-UNESCO for Women in Science program for the field of material science. In July 2012, she introduced the solar cells from the titania clay and pigment of the mangosteen skin on the Recycling and Reuse International Conference in Turkey.

Fatimah's presentation invite the attention of foreign clay experts. Homemade Solar cells use environmentally friendly materials with high abundance. Clay minerals known as widely spread in Indonesia. The skin of the mangosteen is considered as junk, so much was discarded without processing. "The basic material of solar cell is cheap and abundant," she said.

Solar cell experts from the Indonesian's Assessment and Application of Technology Board (Badan Pengkajian dan Penerapan Teknologi/BPPT), Akhmad Kholid, said solar cell from clay and mangosteen peel an attempt by scientists searching for new materials in the field of solar power generation. During this time, the solar cell researchers is constantly looking for new materials that have a high level of efficiency.

DSSC techniques, as applied to the mangosteen clay, he said, still had to be repaired due to technical efficiency rate is still 2-4 percent. For comparison, crystalline silicon materials have 18-19 percent efficiency, whereas the efficiency of thin film materials have 8-9 percent.

Fatimah also confirmed that mangosteen clay has not worked as expected. Tues mangosteen clay that she made, generating voltage by 10 percent than solar cells made from pure titanium oxide. "It is less expensive, but still far less than the solar panels that use synthetic clay," she said. "The quality is not equal with the solar cells made from silicon, plastic, steel or aluminum."

Fatimah estimates instability problem found in mangosteen leather dyes. The mangosteen skin pigment are less capable of binding strength to the maximum light. Another suggestion, the balance quantity of the composition of the mixture of clay and titanium dioxide needs to be changed. "Titania clay that I use for titanium dioxide contains only as much as 5-10 percent of the overall material," said Fatimah.

In recent years, Fatimah optimistic to fix her findings. "Chance of success is still open. Moreover, I have the support of clay experts from China and Australia," she said. Is Fatima believes her research career was destined to be clay. She has decided not to stop learning assessment clay catalysts and materials. "I do not want to switch-over concentration of research. I wanted the most," said master and doctoral degree with "summa cum laude" predicate in the Chemistry Departement of Mathematics and Natural Sciences Faculty, Gadjah Mada University (FMIPA-UGM). *** [ADDI MAWAHIBUN IDHOM | ANTON WILLIAM | KORAN TEMPO 4094]

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