Combined Effect of Titanium Dioxide and Silicon Carbide on Photocatalytic and Mechanical Properties of Concrete

Abstract

This study investigates the challenge of improving concrete's photocatalytic characteristics while maintaining its mechanical strength. The research sought to equilibrate both properties by adding 5% and 7% photocatalysts to the mix. It was done by integrating titanium dioxide (nano-TiO2) and silicon carbide (SiC) in varying quantities by nano-TiO2 to SiC ratio of 4:0, 3:1, 2:2, 1:3 and 0:4. Key findings indicated that in case of nano-TiO2 only, samples with 5% content of nano-TiO2 provided optimal photocatalytic efficacy, achieving 37.7% degradation of methyl orange (MO), further increasing nano-TiO2 resulted in diminished performance. SiC also facilitated photocatalysis, with 7% attaining 7.17% degradation of MO. The amalgamation of nano-TiO2 and SiC enhanced MO degradation, integrating 3:1 content in 5% photocatalyst group achieved a 38.67% MO degradation, exceeding sample having only nano-TiO2 in 5% photocatalytic group, showing synergistic effect. Nonetheless, nano-TiO2 adversely affected mechanical qualities, diminishing strength, whereas SiC improved it. Samples with 7% nano-TiO2 only, attained reduced strength of 14.965 MPa while samples with 5% content of SiC attained a compressive strength of 26.55 MPa, surpassing the control mix of 22.51 MPa. The flexural strength exhibited a comparable pattern i.e. samples with 7% nano-TiO2 only, demonstrating 3.54 MPa and samples with 5% content of SiC attaining 5.7 MPa as compared to 5.24 MPa for control mix. Although SiC enhanced strength, its increased concentration rendered the mix more rigid and brittle. The research determined that the combined content of 2:2 of the 5% photocatalyst group represented the most equilibrated composition, providing mechanical attributes comparable to control mix while markedly enhancing photocatalytic efficiency, so rendering it appropriate for multifunctional applications necessitating both mechanical and photocatalytic features.