Abstracts Book - IMRC 2018

• SF5-O014
SUNLIGHT PHOTOACTIVITY OF TITANIA/BIOGENIC SILICA
CATALYSTS FOR WATER TREATMENT
María C. Fernández de Córdoba 1,2 , Juan Matos 3 , Conchi O. Ania 4
1 CNRS, CEMHTI, POR2E Group, Nanoporous Materials for Energy and Environment, France.
2 Universidad de Oviedo, Química Física y Analítica, Spain. 3 Universidad de Concepción, Hybrid
and Carbon Materials Group, Bioenergy Department, UDT, Chile. 4 CNRS, CEMHTI, POR2E
Group, Nanoporous Materials for Energy and Environment, Univ. Orléans, France.
Biogenic silica obtained rice husks is receiving an increasing attention in the last
years for its use as adsorbent, electrode and catalyst in various application fields
covering wastewater treatment, biomedicine, energy storage in batteries, and
catalysis. In contrast, scarce applications have been reported in solar
photocatalysis, mainly due to the low absorption coefficient in the solar range
of most silica-based materials. In this sense, the main objective of the present
work is to prepare silica-TiO 2 hybrid materials to evaluate their activity for the
photocatalytic degradation of recalcitrant dyes (i.e, rhodamine B) in aqueous
medium under simulated solar light.
In this work, hybrid materials were prepared by the solvothermal treatment of
rice husk (RH) as biogenic precursor in the presence and absence of TiO 2 . The
efficiency of the bare RH-Si and hybrid photocatalysts RH-Si-Ti was evaluated in
the degradation of rhodamine-B under simulated solar light. Data showed that
the prepared catalysts displayed a well-developed mesoporous texture with
non-negligible surface areas ranging 65 to 175 m 2 /g. The calcination at 350 ºC
improved the photocatalytic activity obtained the biogenic precursor by three
times in the absence of TiO 2 . At converse, RH-Si-Ti photocatalyst showed 8 times
higher photoactivity than the calcined sample RH-Si-Ti-350 suggesting a strong
interaction between SiO 2 and TiO 2 along calcination. Results were correlated
with the surface pH and the SiO 2 -TiO 2 crystalline phases. We believe that this
result opens new perspectives for the development of low cost novel biogenicderived
materials with a large potential as photocatalysts for environmental
remediation.
Acknowledgment:
The authors thank the financial support of the grants FONDECYT 1161068, Basal
Program PFB-27, BIOCval2E, and PHOROSOL (ERC-CoG 648161).