STUDYING IMPACT OF CITRIC ACID-BISMUTH NITRATE PENTAHYDRATE RATIO ON PHOTOCATALYTIC ACTIVITY OF BISMUTH OXIDE PREPARED BY SOLUTION COMBUSTION METHOD

Bismuth oxide can be synthesized by solution combustion method. One of parameters that must be considered on the synthesis using this method is fuel-oxidant ratio (φ) since it influences the physicochemical preperties such as morphology, the particle size and crystal structure of the obtained products which further affect on their photocatalyc activity. This research used citric acid as fuel and Bi(NO3)3.5H2O as oxidant. This study aims to investigate impact of citric acid-bismuth nitrate pentahydrate (fuel-oxidant) ratio on the physichochemical properties and photocatalytic activity of the obtained products on degradation of methyl orange. The results showed that all the obtained products contained the mixture of α-Bi2O3 (monoclinic) dan β-Bi2O3 (tetragonal) with irregular shape coral reef-like and in aglomerate form. In addition, the fuel-oxidant ratio does influence the products’ particle size in which the particle size of the products prepared by a ratio of φ>1, φ=1, and φ<1 are about 5-8 μm, 6-10 μm, dan 914 μm, consecutively. Result of photocatalytic activity shows product synthesized with a ratio of > 1 has the highest photocatalytic activity.