Photocatalytic performance of N–TiO2@SiO2 composite obtained under gliding arc plasma processing at atmospheric pressure

Abstract

Photocatalysis is becoming ubiquitous in the chemical industry because of its positive impact on the cost of operations. Nevertheless, a good photocatalyst must meet the properties of good reactivity, high selectivity, long-term stability, low toxicity, and cost-effectiveness but should also promote a photo-generated charge carriers separation. In this work, a homemade supported catalyst is obtained through low-temperature plasma exposure of the precursor TiCl3/glass powder to promote better handling, high particle dispersion, and easy recovery. Because such a plasma is a strongly oxidative medium containing mainly radicals (•OH and NO•), the mixture exposition induces the formation of N–TiO2 nanoparticles immobilized in-situ onto the glass matrix to form a photo-active hetero-structure that improves the charge carriers separation overcoming the rapid recombination drawback. The resulting material was characterized by XRD, FTIR, and SEM techniques. The resilient stability after 5 successive cycles, makes this composite a promising alternative photocatalyst for various applications. The photocatalytic degradation yields reached 52, 72, 60, and 80% within 1 h of plasma irradiation and 45, 43, 22, and 25% after 6 h of daylight illumination, respectively for Rhodamine 6G, Floxina B, Ceftriaxone, and Ampicillin. The discrepancy in degradation yields is more related to the intrinsic chemical structure of each contaminant.

Keywords

• Low-temperature plasma
• Photocatalysis
• Supported-catalyst
• Hetero-structure
• Pharmaceuticals
• Dyes