Transparent self-cleaning coating prepared from SiO2/B4C and SiO2/B4C/TiO2 for the solar cell

Abstract

AbstractTransparent self-cleaning coatings based on photocatalytic activity have attracted great attention in recent years owing to their promising applications in many fields, such as solar cell cover glass. This study reports a simple method to prepare transparent self-cleaning silicon dioxide (SiO2) coatings filled by boron carbide (B4C) and titanium dioxide (TiO2) nanoparticles. A sol-gel technique was used to synthesize a SiO2 solution containing B4C and TiO2 nanoparticles, and a dip-coating technique was followed to coat the composite solution on glass slides. The SiO2 coating was successfully obtained in the presence of both semiconductor nanoparticles as confirmed by FTIR and XRD measurements. Both the photocatalytic activity and self-cleaning property of the composite coatings were evaluated by photocatalytic degradation of a model dye, methylene blue, under visible light irradiation. The SiO2 coating containing both B4C and TiO2 nanoparticles exhibited an improved photocatalytic activity compared to the SiO2 coating including only B4C. In particular, a 46% degradation rate of the model dye methylene blue was achieved for the SiO2 coating containing 15 wt% B4C and 5 wt% TiO2 nanoparticles. Highly transparent composite coatings on glass slides were prepared. The SiO2 coating containing both B4C and TiO2 nanoparticles was found to exhibit ~8% reduction in the optical transmission of the glass slide and ~1% reduction in the efficiency of a solar cell containing the coated glass slide. These findings demonstrated that the SiO2 composite coatings have potential for self-cleaning applications in removing contaminants from the glass cover of the solar cell under visible light irradiation. Graphical Abstract