Silica nanoparticles derived from Arundo donax L. ash composite with Titanium dioxide nanoparticles as an efficient nanocomposite for photocatalytic degradation dye.

Water pollution is a serious problem that threatens both developed and developing countries. Several methods have been used to purify contaminated water, among which the photocatalytic decomposition approach is widely used to purify contaminated water from organic pollutants. In this work, biomass derived SiO2 nanoparticles composite with TiO2 semiconductors used as an efficient photocatalyst for degradation of RhB dye molecules under UV-visible light irradiation is proclaimed. The different weight percentages of Arundo donax L. ash-derived SiO2 nanoparticles combined with TiO2 nanoparticles were prepared through the wet impregnation method. The photocatalytic degradation ability of the as-prepared samples has been scrutinized against the degradation of Rh B dye in which the pronounced photocatalytic degradation efficiency 93.7% is successfully achieved on 50 wt % SiO2-50 wt % TiO2 nanocomposite photocatalyst. The catalytic performance of the nanocomposite decreases with an increase of 50%-75% in SiO2 nanoparticles. There could have been a decrease in degradation efficiency due to an excess amount of SiO2 covering TiO2 nanoparticles, which prevented photons from reaching the nanoparticles. The efficiency of cyclic decomposition of the 50 wt% SiO2-50 wt% TiO2 composite showed only a slight change in photocatalytic capacity compared to the first cycle, which ensures the durability of the sample. However, the hydroxyl radical species play the main role in the degradation process, which has been confirmed by the scavenger test. The probable reaction mechanism is also deliberated in detail. The high photocatalytic performance of novel eco-friendly SiO2-TiO2 photocatalyst make it ideal for water purification applications.