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

Abstract

Transparent 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