The Use of Rice Husk Silica in Modified Zinc Oxide Photocatalysts to Reduce Chromium Concentration

Diana Rakhmawaty Eddy (Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran Jl. Raya Bandung Sumedang km 21 Jatinangor, Sumedang, 45363, Indonesia)
L Ahmad Na’ani (Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran Jl. Raya Bandung Sumedang km 21 Jatinangor, Sumedang, 45363, Indonesia)
Rustaman Rustaman (Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran Jl. Raya Bandung Sumedang km 21 Jatinangor, Sumedang, 45363, Indonesia)
Solihudin Solihudin (Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran Jl. Raya Bandung Sumedang km 21 Jatinangor, Sumedang, 45363, Indonesia)

VALENSI
Jurnal Kimia VALENSI Volume 6, No. 1, May 2020

Rice husk ash contains approximately 90-98% dry weight of silica and they have been reported to have several advantages compared to mineral silica. One of these is its application as a filler in ZnO photocatalysts using the sol-gel method. This study was, therefore, conducted to determine the effect of adding rice husk silica to increase the ability of ZnO/SiO2 photocatalyst to reduce chromium concentration. Meanwhile, a previous effort has been made to degrade methylene blue dyes by 89%. This current research involved preparing rice husk charcoal using pyrolysis tubes after which they were extracted to produce silica while ZnO/SiO2 composites were made at a 95/5, 90/10, and 85/15 (w/w) ratio and composite activity test was conducted to determine its ability to reduce chromium concentration from practicum discharge. The SEM-EDS results showed the formation of SiO2 composites in ZnO while 82.6% decrease in total chromium concentration from waste was obtained after 2 hours irradiation with 95/5 composites using ultraviolet radiation.